diff --git a/package.json b/package.json
index 7241b81..b3b4f81 100644
--- a/package.json
+++ b/package.json
@@ -13,17 +13,19 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
-    "@szhsin/react-menu": "^3.0.2",
+    "@szhsin/react-menu": "^3.1.2",
     "@types/": "szhsin/react-menu",
     "@types/eventemitter2": "^4.1.0",
     "@types/styled-jsx": "^3.4.4",
     "@types/uuid": "^8.3.4",
     "eventemitter2": "^6.4.7",
     "mancala.js": "^0.0.2-beta.3",
+    "notyf": "^3.10.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-router-dom": "6",
     "styled-jsx": "^5.0.2",
+    "sweetalert": "^2.1.2",
     "uuid": "^8.3.2"
   },
   "devDependencies": {
diff --git a/src/MancalaApp.tsx b/src/MancalaApp.tsx
index ba62f58..b35675d 100644
--- a/src/MancalaApp.tsx
+++ b/src/MancalaApp.tsx
@@ -12,9 +12,11 @@ import Home from './routes/Home';
 import { initContext } from './context/context';
 import { RTMTWS } from './rtmt/rtmt_websocket';
 import { getColorByBrightness } from './util/ColorUtil';
-import { ConnectionState } from './models/ConnectionState';
 import { Theme } from './theme/Theme';
 import LobyPage from './routes/LobyPage';
+import swal from 'sweetalert';
+import { ConnectionState } from './rtmt/rtmt';
+
 const context = initContext();
 
 const MancalaApp: FunctionComponent = () => {
@@ -40,9 +42,15 @@ const MancalaApp: FunctionComponent = () => {
         setTheme(theme)
     }
     const connectToServer = async () => {
-        const userKey = await context.userKeyStore.getUserKey();
-        setUserKey(userKey);
-        (context.rtmt as RTMTWS).initWebSocket(userKey);
+        try {
+            const userKey = await context.userKeyStore.getUserKey();
+            setUserKey(userKey);
+            (context.rtmt as RTMTWS).initWebSocket(userKey);
+        } catch (error) {
+            //TODO: check if it is network error!
+            swal(context.texts.Error + "!", context.texts.ErrorWhenRetrievingInformation, "error");
+            console.error(error);
+        }
     };
 
     React.useEffect(() => {
@@ -74,7 +82,6 @@ const MancalaApp: FunctionComponent = () => {
         context.themeManager.theme.textColor,
         context.themeManager.theme.textLightColor
     );
-    if (!userKey) return <></>;
     return (
         <>
             <BrowserRouter>
@@ -82,7 +89,7 @@ const MancalaApp: FunctionComponent = () => {
                     <Route index element={<Home context={context} theme={theme} userKey={userKey} />} />
                     <Route path="/" >
                         <Route path="game" >
-                            <Route path=":gameId" element={<GamePage context={context} theme={theme} userKey={userKey} connectionState={connectionState} />}  ></Route>
+                            <Route path=":gameId" element={<GamePage context={context} theme={theme} userKey={userKey} />}  ></Route>
                         </Route>
                         <Route path="loby" element={<LobyPage context={context} theme={theme} userKey={userKey} />}>
                         </Route>
@@ -90,7 +97,7 @@ const MancalaApp: FunctionComponent = () => {
                 </Routes>
             </BrowserRouter>
             <FloatingPanel context={context} color={floatingPanelColor} visible={showConnectionState}>
-                <span style={{ color: textColorOnBoard }}>{connectionStateText()}</span>
+                <span style={{ color: textColorOnBoard, transition: 'color 0.5s' }}>{connectionStateText()}</span>
             </FloatingPanel>
         </>
     );
diff --git a/src/animation/PitAnimator.ts b/src/animation/PitAnimator.ts
index 4db6dc3..ffcdf84 100644
--- a/src/animation/PitAnimator.ts
+++ b/src/animation/PitAnimator.ts
@@ -13,6 +13,7 @@ import { Context } from "../context/context";
 import BoardViewModelFactory from "../factory/BoardViewModelFactory";
 import { PitViewModelFactory } from "../factory/PitViewModelFactory";
 import { Game } from "../models/Game";
+import { Theme } from "../theme/Theme";
 import { getColorByBrightness } from "../util/ColorUtil";
 import BoardViewModel from "../viewmodel/BoardViewModel";
 
@@ -35,6 +36,7 @@ export default class PitAnimator {
   ) {
     this.context = context;
     this.onBoardViewModelUpdate = onBoardViewModelUpdate;
+    this.context.themeManager.on("themechange", this.onThemeChange.bind(this));
   }
 
   get mancalaGame(): MancalaGame | undefined {
@@ -190,6 +192,11 @@ export default class PitAnimator {
     });
   }
 
+  private onThemeChange(theme: Theme){
+    if(!this.game) return;
+    this.onBoardViewModelUpdate?.(this.getBoardViewModelFromGame(this.game));
+  }
+
   public resetAnimationState() {
     this.animationIndex = -1;
     this.currentHistoryItem = undefined;
@@ -204,6 +211,7 @@ export default class PitAnimator {
   }
 
   public dispose() {
+    this.context.themeManager.off("themechange", this.onThemeChange.bind(this));
     this.resetAnimationState();
     this.clearCurrentInterval();
   }
diff --git a/src/components/Button.tsx b/src/components/Button.tsx
index 6c09a2c..620e3e1 100644
--- a/src/components/Button.tsx
+++ b/src/components/Button.tsx
@@ -18,7 +18,7 @@ const Button: FunctionComponent<{
     <button
       onClick={onClick}
       style={{
-        background: color,
+        backgroundColor: color,
         color: textColor,
       }}
     >
@@ -28,6 +28,9 @@ const Button: FunctionComponent<{
           padding: 10px;
           border: none;
           border-radius: 30px;
+          transition: color 0.5s; 
+          transition: background-color 0.5s; 
+          white-space: nowrap;
         }
       `}</style>
       {text}
diff --git a/src/components/CircularPanel.tsx b/src/components/CircularPanel.tsx
index 83d7dec..2de9283 100644
--- a/src/components/CircularPanel.tsx
+++ b/src/components/CircularPanel.tsx
@@ -11,6 +11,8 @@ const CircularPanel: FunctionComponent<{
             div {
               padding: 10px 20px;
               border-radius: 30px;
+              transition: background-color 0.5s;
+              white-space: nowrap;
             }
           `}
       </style>
diff --git a/src/components/InfoPanel.tsx b/src/components/InfoPanel.tsx
index 5ccbafc..59545fb 100644
--- a/src/components/InfoPanel.tsx
+++ b/src/components/InfoPanel.tsx
@@ -99,7 +99,7 @@ const InfoPanel: FunctionComponent<{
     if (text) {
       return (
         <CircularPanel style={style} color={containerColor}>
-          <h4 style={{ margin: "0", color: textColor }}>
+          <h4 style={{ margin: "0", color: textColor, transition: 'color 0.5s' }}>
             {text}
           </h4>
         </CircularPanel>
diff --git a/src/components/PageContainer.tsx b/src/components/PageContainer.tsx
index 82233f4..7d08f57 100644
--- a/src/components/PageContainer.tsx
+++ b/src/components/PageContainer.tsx
@@ -14,6 +14,7 @@ const PageContainer: FunctionComponent<{ theme: Theme }> = (props) => {
                     align-items: center;
                     flex: 1;
                     min-height: 400px;
+                    transition: background-color 0.5s;
                 }
             `}</style>
             {props.children}
diff --git a/src/components/UserStatus.tsx b/src/components/UserStatus.tsx
index 20b061b..82882ff 100644
--- a/src/components/UserStatus.tsx
+++ b/src/components/UserStatus.tsx
@@ -16,17 +16,13 @@ const UserStatus: FunctionComponent<{
 }> = ({ context, user, layoutMode, visible, style }) => {
     if (visible === false) return <></>;
     const textColorOnBoard = getColorByBrightness(
-        context.themeManager.theme.boardColor,
+        context.themeManager.theme.background,
         context.themeManager.theme.textColor,
         context.themeManager.theme.textLightColor
     );
     return (
         <div style={style} className={layoutMode === "right" ? "flex-rtl" : "flex-ltr"}>
-            <span style={{color: textColorOnBoard}} className="material-symbols-outlined icon" >
-                face_6
-            </span>
-            <Space width='5px' />
-            <span style={{color: textColorOnBoard}} className='text'>{user.isAnonymous ? context.texts.Anonymous : user.name}</span>
+            <span style={{color: textColorOnBoard, transition: 'color 0.5s'}} className='text'>{user.isAnonymous ? context.texts.Anonymous : user.name}</span>
             <Space width='5px' />
             <div className={"circle " + (user.isOnline ? "online" : "offline")}></div>
             <style jsx>{`
@@ -43,6 +39,8 @@ const UserStatus: FunctionComponent<{
                     min-height: 15px;
                     border-radius: 15px;
                     border: 2px solid ${context.themeManager.theme.boardColor};
+                    transition: background-color 0.5s;
+                    transition: color 0.5s;
                 }
                 .flex-rtl {
                     display: flex;
diff --git a/src/components/board/StoreView.tsx b/src/components/board/StoreView.tsx
index 58f762e..db5dd3d 100644
--- a/src/components/board/StoreView.tsx
+++ b/src/components/board/StoreView.tsx
@@ -29,7 +29,7 @@ const StoreView: FunctionComponent<{
         gridRow: gridRow
       }}>
       {stones}
-      <span className="store-stone-count-text" style={{ color: textColor }}>
+      <span className="store-stone-count-text" style={{ color: textColor, transition: 'color 0.5s' }}>
         {stones.length}
       </span>
       <style jsx>{`
@@ -42,6 +42,7 @@ const StoreView: FunctionComponent<{
             align-content: center;
             flex-wrap: wrap;
             position: relative;
+            transition: background-color 0.5s;
           }
           .store-stone-count-text {
             position: absolute;
diff --git a/src/components/headerbar/HeaderBar.tsx b/src/components/headerbar/HeaderBar.tsx
index 826c4c2..683f8c2 100644
--- a/src/components/headerbar/HeaderBar.tsx
+++ b/src/components/headerbar/HeaderBar.tsx
@@ -13,6 +13,7 @@ const HeaderBar: FunctionComponent<{ color?: string }> = ({children, color }) =>
                 align-items: center;
                 justify-content: space-between;
                 align-self: stretch;
+                transition: background-color 0.5s;
             }
             `}</style>
         </div>)
diff --git a/src/components/headerbar/HeaderbarTitle.tsx b/src/components/headerbar/HeaderbarTitle.tsx
index 2da3039..25174e5 100644
--- a/src/components/headerbar/HeaderbarTitle.tsx
+++ b/src/components/headerbar/HeaderbarTitle.tsx
@@ -4,7 +4,7 @@ import { Context } from '../../context/context';
 
 const HeaderbarTitle: FunctionComponent<{ title: string, color: string }> = ({ title, color }) => {
     return (
-        <h1 style={{ color: color }} className="header-bar-title">
+        <h1 style={{ color: color, transition: 'color 0.5s' }} className="header-bar-title">
             {title}
             <style jsx>{`
             .header-bar-title {
diff --git a/src/components/headerbar/ThemeSwitchMenu.tsx b/src/components/headerbar/ThemeSwitchMenu.tsx
index 73cb535..6e45818 100644
--- a/src/components/headerbar/ThemeSwitchMenu.tsx
+++ b/src/components/headerbar/ThemeSwitchMenu.tsx
@@ -8,22 +8,27 @@ import "@szhsin/react-menu/dist/transitions/slide.css"
 const ThemeSwitchMenu: FunctionComponent<{ context: Context, textColor: string }> = (props) => {
     const { context, textColor } = props;
     const menuButton = <span
-        style={{ color: textColor }}
+        style={{ color: textColor, cursor: 'pointer', userSelect: 'none' }}
         className="material-symbols-outlined">
         light_mode
     </span>;
     const menuItems = context.themeManager.themes.map((theme, index) => {
-        const themeBackground = context.themeManager.theme.background;
         return (
             <MenuItem
                 key={index}
                 style={{ color: textColor }}
                 //@ts-ignore
-                onMouseOver={(event) => (event.target.style.background = themeBackground)}
+                onMouseOver={(event) => {
+                    const htmlElement: HTMLElement = event.target as HTMLElement;
+                    if (htmlElement.localName === "li") htmlElement.style.background = "transparent";
+                }}
                 //@ts-ignore
-                onMouseOut={(event) => (event.target.style.background = "transparent")}
+                onMouseOut={(event) => {
+                    const htmlElement: HTMLElement = event.target as HTMLElement;
+                    if (htmlElement.localName === "li") htmlElement.style.background = "transparent";
+                }}
                 onClick={() => (context.themeManager.theme = theme)}>
-                <div style={{ background: theme.boardColor }} className="theme-color-circle" />
+                <div style={{ background: theme.themePreviewColor }} className="theme-color-circle" />
                 {theme.name}
                 <style jsx>{`
                 .theme-color-circle {
diff --git a/src/const/texts.ts b/src/const/texts.ts
index cf8cfce..273cc72 100644
--- a/src/const/texts.ts
+++ b/src/const/texts.ts
@@ -6,7 +6,7 @@ export type Texts = {
     YourTurn: string,
     OpponentTurn: string,
     GameEnded: string,
-    GameCrashed: string,
+    InternalErrorOccurred: string,
     YouWon: string,
     Won: string,
     YouLost: string,
@@ -21,12 +21,20 @@ export type Texts = {
     YouLeftTheGame: string,
     UserLeftTheGame: string,
     SearchingOpponent: string,
-    PleaseWait : string,
-    GameDraw : string,
+    PleaseWait: string,
+    GameDraw: string,
     Anonymous: string,
     GameNotFound: string,
     Loading: string,
     Playing: string,
+    Error: string,
+    ErrorWhenRetrievingInformation: string,
+    UCanOnlyPlayYourOwnPits: string,
+    UMustWaitUntilCurrentMoveComplete: string,
+    UCanNotPlayEmptyPit: string,
+    AreYouSureToLeaveGame: string,
+    Yes: string,
+    Cancel: string,
 }
 
 export const EnUs: Texts = {
@@ -36,14 +44,14 @@ export const EnUs: Texts = {
     YourTurn: "Your Turn",
     OpponentTurn: "Opponent Turn",
     GameEnded: "Game Ended",
-    GameCrashed: "Game Crashed",
+    InternalErrorOccurred: "An internal error has occurred",
     YouWon: "You Won",
     Won: "Won",
     YouLost: "You Lost",
     Connecting: "Connecting",
     Connected: "Connected",
     CannotConnect: "Can't Connect",
-    ConnectionLost: "Connection Lost",
+    ConnectionLost: "Network Connection Lost",
     ConnectingAgain: "Connecting Again",
     ServerError: "Server Error",
     SearchingOpponet: "Searching Opponet",
@@ -51,12 +59,20 @@ export const EnUs: Texts = {
     YouLeftTheGame: "You Left The Game",
     UserLeftTheGame: "Left The Game",
     SearchingOpponent: "Searching Opponent",
-    PleaseWait : "Please Wait",
-    GameDraw : "Draw",
+    PleaseWait: "Please Wait",
+    GameDraw: "Draw",
     Anonymous: "Anonymous",
     GameNotFound: "Game Not Found",
     Loading: "Loading",
     Playing: "Playing",
+    Error: "Error",
+    ErrorWhenRetrievingInformation: "An error occured when retrieving information!",
+    UCanOnlyPlayYourOwnPits: "You can only play your own pits",
+    UMustWaitUntilCurrentMoveComplete: "You must wait until the current move is complete",
+    UCanNotPlayEmptyPit: "You can not play empty pit",
+    AreYouSureToLeaveGame: "Are you sure to leave game?",
+    Yes: "Yes",
+    Cancel: "Cancel",
 }
 
 export const TrTr: Texts = {
@@ -66,14 +82,14 @@ export const TrTr: Texts = {
     YourTurn: "Sıra Sende",
     OpponentTurn: "Sıra Rakipte",
     GameEnded: "Oyun Bitti",
-    GameCrashed: "Oyunda Hata Oluştu",
+    InternalErrorOccurred: "Dahili bir hata oluştu",
     YouWon: "Kazandın",
     Won: "Kazandı",
     YouLost: "Kaybettin",
     Connecting: "Bağlanılıyor",
     Connected: "Bağlandı",
     CannotConnect: "Bağlanılamadı",
-    ConnectionLost: "Bağlantı Koptu",
+    ConnectionLost: "Ağ Bağlantısı Koptu",
     ConnectingAgain: "Tekrar Bağlanılıyor",
     ServerError: "Sunucu Hatası",
     SearchingOpponet: "Rakip Aranıyor",
@@ -82,9 +98,17 @@ export const TrTr: Texts = {
     UserLeftTheGame: "Oyundan Ayrıldı",
     SearchingOpponent: "Rakip Aranıyor",
     PleaseWait: "Lütfen Bekleyin",
-    GameDraw : "Berabere",
+    GameDraw: "Berabere",
     Anonymous: "Anonim",
     GameNotFound: "Oyun Bulunamadı",
     Loading: "Yükleniyor",
     Playing: "Oynuyor",
+    Error: "Hata",
+    ErrorWhenRetrievingInformation: "Bilgiler toplanırken bir hata oluştu!",
+    UCanOnlyPlayYourOwnPits: "Sadece sana ait olan kuyular ile oynayabilirsin",
+    UMustWaitUntilCurrentMoveComplete: "Devam eden haraketin bitmesini beklemelisin",
+    UCanNotPlayEmptyPit: "Boş kuyu ile oynayamazsın",
+    AreYouSureToLeaveGame: "Oyundan ayrılmak istediğine emin misin?",
+    Yes: "Evet",
+    Cancel: "İptal"
 }
\ No newline at end of file
diff --git a/src/models/ConnectionState.ts b/src/models/ConnectionState.ts
deleted file mode 100644
index 5010944..0000000
--- a/src/models/ConnectionState.ts
+++ /dev/null
@@ -1 +0,0 @@
-export type ConnectionState = "connecting" | "error" | "connected" | "reconnecting";
\ No newline at end of file
diff --git a/src/routes/GamePage.tsx b/src/routes/GamePage.tsx
index 6ec6e64..331d841 100644
--- a/src/routes/GamePage.tsx
+++ b/src/routes/GamePage.tsx
@@ -20,7 +20,6 @@ import UserStatus from '../components/UserStatus';
 import { channel_on_game_update, channel_on_game_crashed, channel_on_game_user_leave, channel_on_user_connection_change, channel_leave_game, channel_game_move, channel_listen_game_events, channel_unlisten_game_events } from '../const/channel_names';
 import { Context } from '../context/context';
 import useWindowDimensions from '../hooks/useWindowDimensions';
-import { ConnectionState } from '../models/ConnectionState';
 import { GameMove } from '../models/GameMove';
 import { LoadingState } from '../models/LoadingState';
 import { Theme } from '../theme/Theme';
@@ -28,13 +27,15 @@ import { getColorByBrightness } from '../util/ColorUtil';
 import BoardViewModel from '../viewmodel/BoardViewModel';
 import Center from '../components/Center';
 import { Game, GameUsersConnectionInfo } from '../models/Game';
+import notyf from '../util/Notyf';
+import swal from 'sweetalert';
+import Util from '../util/Util';
 
 const GamePage: FunctionComponent<{
     context: Context,
     userKey?: string,
     theme: Theme,
-    connectionState: ConnectionState
-}> = ({ context, userKey, theme, connectionState }) => {
+}> = ({ context, userKey, theme }) => {
     let params = useParams<{ gameId: string }>();
 
     const [game, setGame] = useState<Game | undefined>(undefined);
@@ -89,6 +90,7 @@ const GamePage: FunctionComponent<{
     }
     const onGameCrashed = (message: any) => {
         const newCrashMessage = message as string;
+        notyf.error(context.texts.InternalErrorOccurred);
         console.error("on_game_crash");
         console.error(newCrashMessage);
     }
@@ -136,10 +138,22 @@ const GamePage: FunctionComponent<{
     const checkHasAnOngoingAction = () => hasOngoingAction;
 
     const onLeaveGameClick = () => {
-        context.rtmt.sendMessage(channel_leave_game, {});
+        if(Util.checkConnectionAndMaybeAlert(context)) return;
+        swal({
+            title: context.texts.AreYouSureToLeaveGame,
+            icon: "warning",
+            buttons: [context.texts.Yes, context.texts.Cancel],
+            dangerMode: true,
+        })
+            .then((cancel) => {
+                if (!cancel) {
+                    context.rtmt.sendMessage(channel_leave_game, {});
+                }
+            });
     };
 
     const onNewGameClick = () => {
+        if(Util.checkConnectionAndMaybeAlert(context)) return;
         navigate("/loby")
     };
 
@@ -147,21 +161,27 @@ const GamePage: FunctionComponent<{
         if (!game || isSpectator || !userKey) {
             return;
         }
+        if (game.mancalaGame.getPlayerIdByIndex(index) !== userKey) {
+            notyf.error(context.texts.UCanOnlyPlayYourOwnPits);
+            return;
+        }
         const pitIndexForUser = index % (game.mancalaGame.board.totalPitCount() / 2);
-        if (game.mancalaGame.getPlayerIdByIndex(index) !== userKey ||
-            !game.mancalaGame.canPlayerMove(userKey, pitIndexForUser)) {
+        if (!game.mancalaGame.canPlayerMove(userKey, pitIndexForUser)) {
+            notyf.error(context.texts.OpponentTurn);
             return;
         }
         if (checkHasAnOngoingAction()) {
+            notyf.error(context.texts.UMustWaitUntilCurrentMoveComplete);
             return;
         }
-        setHasOngoingAction(true);
+        if(Util.checkConnectionAndMaybeAlert(context)) return;
         if (!boardViewModel) return;
         //TODO: this check should be in mancala.js
         if (pit.stoneCount === 0) {
-            //TODO : warn user
+            notyf.error(context.texts.UCanNotPlayEmptyPit);
             return;
         }
+        setHasOngoingAction(true);
         boardViewModel.pits[getBoardIndex(pitIndexForUser)].pitColor =
             context.themeManager.theme.pitSelectedColor;
         updateBoardViewModel(boardViewModel);
@@ -210,13 +230,13 @@ const GamePage: FunctionComponent<{
     const bottomLocatedUser = {
         id: bottomLocatedUserId,
         name: "Anonymous",
-        isOnline: isSpectator ? isUserOnline(bottomLocatedUserId) : connectionState === "connected",
+        isOnline: isSpectator ? isUserOnline(bottomLocatedUserId) : context.rtmt.connectionState === "connected",
         isAnonymous: true
     };
     const currentUser = isSpectator ? {
         id: "2",
         name: "Anonymous",
-        isOnline: connectionState === "connected",
+        isOnline: context.rtmt.connectionState === "connected",
         isAnonymous: true
     } : bottomLocatedUser;
     const leftPlayer = userKeyWhoLeave ? (userKeyWhoLeave === topLocatedUser.id ? topLocatedUser : bottomLocatedUser) : undefined;
@@ -263,7 +283,7 @@ const GamePage: FunctionComponent<{
 
     function renderMobileBoardToolbar() {
         return <BoardToolbar style={{ justifyContent: "center" }} visible={showBoardView && isMobile || false}>
-            {buildInfoPanel()}
+            {buildInfoPanel({ visible: isMobile })}
         </BoardToolbar>;
     }
 
@@ -273,7 +293,7 @@ const GamePage: FunctionComponent<{
                 marginBottom: "0.5rem", marginLeft: "6%", maxWidth: isMobile ? "40vw" : "30vw",
                 width: isMobile ? "40vw" : "30vw"
             }} context={context} layoutMode="left" user={topLocatedUser} visible={showBoardView || false} />
-            {buildInfoPanel()}
+            {buildInfoPanel({ visible: !isMobile })}
             <UserStatus style={{
                 marginBottom: "0.5rem", marginRight: "6%", maxWidth: isMobile ? "40vw" : "30vw",
                 width: isMobile ? "40vw" : "30vw"
@@ -281,7 +301,7 @@ const GamePage: FunctionComponent<{
         </BoardToolbar>;
     }
 
-    function buildInfoPanel() {
+    function buildInfoPanel(params: { visible: boolean }) {
         return (
             <InfoPanel
                 style={{ marginTop: "0.5rem", marginBottom: "0.5rem" }}
@@ -291,7 +311,7 @@ const GamePage: FunctionComponent<{
                 whitePlayer={topLocatedUser}
                 blackPlayer={bottomLocatedUser}
                 leftPlayer={leftPlayer}
-                visible={!isMobile}
+                visible={params.visible}
                 isSpectator={isSpectator} />
         );
     }
diff --git a/src/routes/Home.tsx b/src/routes/Home.tsx
index c37b345..268589c 100644
--- a/src/routes/Home.tsx
+++ b/src/routes/Home.tsx
@@ -11,6 +11,7 @@ import ThemeSwitchMenu from "../components/headerbar/ThemeSwitchMenu";
 import Button from "../components/Button";
 import { Context } from "../context/context";
 import { Link, useNavigate } from "react-router-dom";
+import Util from "../util/Util";
 
 const Home: FunctionComponent<{
   context: Context,
@@ -21,6 +22,7 @@ const Home: FunctionComponent<{
   const navigate = useNavigate();
 
   const onNewGameClick = () => {
+    if(Util.checkConnectionAndMaybeAlert(context)) return;
     navigate("/loby")
   };
 
diff --git a/src/rtmt/rtmt.ts b/src/rtmt/rtmt.ts
index 4e5e010..499a8a0 100644
--- a/src/rtmt/rtmt.ts
+++ b/src/rtmt/rtmt.ts
@@ -3,10 +3,12 @@ import EventEmitter2, { Listener } from "eventemitter2"
 export type Bytes = Uint8Array
 export type OnMessage = (message : Object) => any
 
+export type ConnectionState = "none" | "connecting" | "error" | "connected" | "closed" | "reconnecting";
 
 export type RtmtEventTypes = "open" | "close" | "connected" | "error" | "disconnected" | "message";
 
 export interface RTMT extends EventEmitter2 {
+    get connectionState() : ConnectionState;
     sendMessage: (channel: string, message: Object) => void;
     addMessageListener(channel: string, callback: (message: any) => void);
     removeMessageListener(channel: string, callback: (message: any) => void);
diff --git a/src/rtmt/rtmt_websocket.ts b/src/rtmt/rtmt_websocket.ts
index a60d2e4..2117618 100644
--- a/src/rtmt/rtmt_websocket.ts
+++ b/src/rtmt/rtmt_websocket.ts
@@ -2,7 +2,7 @@ import { decode, encode } from "./encode_decode_message";
 import { channel_ping, channel_pong } from "../const/channel_names";
 import { server } from "../const/config";
 import EventEmitter2, { Listener } from "eventemitter2";
-import { Bytes, RTMT, RtmtEventTypes } from "./rtmt";
+import { Bytes, ConnectionState, RTMT, RtmtEventTypes } from "./rtmt";
 
 const PING_INTERVAL = 15000, PING_INTERVAL_BUFFER_TIME = 1000;
 const MESSAGE_CHANNEL_PREFIX = "message_channel";
@@ -10,24 +10,32 @@ const MESSAGE_CHANNEL_PREFIX = "message_channel";
 export class RTMTWS extends EventEmitter2 implements RTMT {
   private webSocket: WebSocket;
   private pingTimeout?: number = undefined;
+  private _connectionState: ConnectionState = "none";
 
   constructor() {
     super();
   }
 
+  get connectionState(): ConnectionState {
+    return this._connectionState;
+  }
+
   public initWebSocket(userKey: string) {
+    this._connectionState = this._connectionState !== "none" ? "reconnecting" : "connecting";
     const url = server.wsServerAdress + "?userKey=" + userKey;
     const webSocket = new WebSocket(url);
     webSocket.onopen = () => {
       console.info("(RTMT) WebSocket has opened");
       this.webSocket = webSocket;
       this.heartbeat();
+      this._connectionState = "connected";
       this.emit("open");
     };
     webSocket.onclose = () => {
       console.info("(RTMT) WebSocket has closed");
       //this.WebSocket = undefined
       clearTimeout(this.pingTimeout);
+      this._connectionState = "closed";
       this.emit("close");
     };
     webSocket.onmessage = (event: MessageEvent) => {
@@ -36,6 +44,7 @@ export class RTMTWS extends EventEmitter2 implements RTMT {
     };
     webSocket.onerror = (error) => {
       console.error(error);
+      this._connectionState = "error";
       this.emit("error", error);
     }
   }
diff --git a/src/theme/DarkTheme.ts b/src/theme/DarkTheme.ts
index 1a081c9..625aff2 100644
--- a/src/theme/DarkTheme.ts
+++ b/src/theme/DarkTheme.ts
@@ -13,6 +13,7 @@ const colorSpecial = "#337a44";
 const darkTheme: Theme = {
   id: "2",
   name: "Dark Theme",
+  themePreviewColor: colors.primary,
   background: colors.primary,
   appBarBgColor: colors.secondary,
   textColor: colors.primary,
diff --git a/src/theme/GreyTheme.ts b/src/theme/GreyTheme.ts
index f8b4a80..448e8c9 100644
--- a/src/theme/GreyTheme.ts
+++ b/src/theme/GreyTheme.ts
@@ -3,6 +3,7 @@ import { Theme } from "./Theme";
 const greyTheme: Theme = {
   id: "1",
   name: "Grey Theme",
+  themePreviewColor: "#4D606E",
   background: "#EEEEEE",
   appBarBgColor: "#e4e4e4",
   textColor: "#4D606E",
diff --git a/src/theme/LightTheme.ts b/src/theme/LightTheme.ts
index bdcbbdf..e81d5e4 100644
--- a/src/theme/LightTheme.ts
+++ b/src/theme/LightTheme.ts
@@ -5,6 +5,7 @@ const colorSpecial = "#8B8B8B";
 const lightTheme: Theme = {
   id: "1",
   name: "Light Theme",
+  themePreviewColor: "#9B9B9B",
   background: "#BBBBBB",
   appBarBgColor: "#7B7B7B",
   textColor: "#5B5B5B",
diff --git a/src/theme/Theme.ts b/src/theme/Theme.ts
index b4067e0..11fa3f6 100644
--- a/src/theme/Theme.ts
+++ b/src/theme/Theme.ts
@@ -1,6 +1,7 @@
 export type Theme = {
   id: string;
   name: string;
+  themePreviewColor: string; // for theme switch menu
   textColor: string;
   textLightColor: string;
   background: string;
diff --git a/src/util/Notyf.ts b/src/util/Notyf.ts
new file mode 100644
index 0000000..753a1f7
--- /dev/null
+++ b/src/util/Notyf.ts
@@ -0,0 +1,4 @@
+import { Notyf } from 'notyf';
+import 'notyf/notyf.min.css'; 
+const notyf = new Notyf();
+export default notyf;
\ No newline at end of file
diff --git a/src/util/Util.ts b/src/util/Util.ts
index 5898bbf..cf27332 100644
--- a/src/util/Util.ts
+++ b/src/util/Util.ts
@@ -1,10 +1,20 @@
+import { Context } from "../context/context";
+import notyf from "./Notyf";
 
 export default class Util {
     public static range(size: number) {
-        var ans : number[] = [];
+        var ans: number[] = [];
         for (let i = 0; i < size; i++) {
             ans.push(i);
         }
         return ans;
     }
+
+    public static checkConnectionAndMaybeAlert(context: Context): boolean {
+        if (context.rtmt.connectionState !== "connected") {
+            notyf.error(context.texts.ConnectionLost);
+            return true;
+        }
+        return false;
+    }
 }
diff --git a/yarn.lock b/yarn.lock
index bcb2a71..0bbdc99 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1067,10 +1067,10 @@
   dependencies:
     tslib "^2.4.0"
 
-"@szhsin/react-menu@^3.0.2":
-  version "3.0.2"
-  resolved "https://registry.yarnpkg.com/@szhsin/react-menu/-/react-menu-3.0.2.tgz#d22971c53d56e6d404c9d3c98f533907cd8f03dc"
-  integrity sha512-m9Ly+cT+CxQx3xhq90CVaOLQWU7f7UKeMxfDt1gPYV23tDwEe8Zo6PO547qPlAEGEwwb9MdA38U8OyueXKJc2g==
+"@szhsin/react-menu@^3.1.2":
+  version "3.1.2"
+  resolved "https://registry.yarnpkg.com/@szhsin/react-menu/-/react-menu-3.1.2.tgz#3a791e7e6c672d113c298985bec5185e9c7aa8a7"
+  integrity sha512-NUnU429a3jXtRD4xxk8EsR4yRSuhZPWAkI+4P4K63LQPUZGVE7adVKtEmlyOpd8CRQ7aoUz1ZLr1VmR1nZi6GQ==
   dependencies:
     prop-types "^15.7.2"
     react-transition-state "^1.1.4"
@@ -1418,6 +1418,11 @@ error-ex@^1.3.1:
   dependencies:
     is-arrayish "^0.2.1"
 
+es6-object-assign@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/es6-object-assign/-/es6-object-assign-1.1.0.tgz#c2c3582656247c39ea107cb1e6652b6f9f24523c"
+  integrity sha512-MEl9uirslVwqQU369iHNWZXsI8yaZYGg/D65aOgZkeyFJwHYSxilf7rQzXKI7DdDuBPrBXbfk3sl9hJhmd5AUw==
+
 escalade@^3.1.1:
   version "3.1.1"
   resolved "https://registry.npmjs.org/escalade/-/escalade-3.1.1.tgz"
@@ -1630,6 +1635,11 @@ node-releases@^2.0.6:
   resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-2.0.6.tgz#8a7088c63a55e493845683ebf3c828d8c51c5503"
   integrity sha512-PiVXnNuFm5+iYkLBNeq5211hvO38y63T0i2KKh2KnUs3RpzJ+JtODFjkD8yjLwnDkTYF1eKXheUwdssR+NRZdg==
 
+notyf@^3.10.0:
+  version "3.10.0"
+  resolved "https://registry.yarnpkg.com/notyf/-/notyf-3.10.0.tgz#67a64443c69ea0e6495c56ea0f91198860163d06"
+  integrity sha512-Mtnp+0qiZxgrH+TzVlzhWyZceHdAZ/UWK0/ju9U0HQeDpap1mZ8cC7H5wSI5mwgni6yeAjaxsTw0sbMK+aSuHw==
+
 nth-check@^2.0.1:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/nth-check/-/nth-check-2.1.1.tgz#c9eab428effce36cd6b92c924bdb000ef1f1ed1d"
@@ -1738,6 +1748,11 @@ process@^0.11.10:
   resolved "https://registry.yarnpkg.com/process/-/process-0.11.10.tgz#7332300e840161bda3e69a1d1d91a7d4bc16f182"
   integrity sha512-cdGef/drWFoydD1JsMzuFf8100nZl+GT+yacc2bEced5f9Rjk4z+WtFUTBu9PhOi9j/jfmBPu0mMEY4wIdAF8A==
 
+promise-polyfill@^6.0.2:
+  version "6.1.0"
+  resolved "https://registry.yarnpkg.com/promise-polyfill/-/promise-polyfill-6.1.0.tgz#dfa96943ea9c121fca4de9b5868cb39d3472e057"
+  integrity sha512-g0LWaH0gFsxovsU7R5LrrhHhWAWiHRnh1GPrhXnPgYsDkIqjRYUYSZEsej/wtleDrz5xVSIDbeKfidztp2XHFQ==
+
 prop-types@^15.7.2:
   version "15.8.1"
   resolved "https://registry.yarnpkg.com/prop-types/-/prop-types-15.8.1.tgz#67d87bf1a694f48435cf332c24af10214a3140b5"
@@ -1884,6 +1899,14 @@ svgo@^2.4.0, svgo@^2.5.0:
     picocolors "^1.0.0"
     stable "^0.1.8"
 
+sweetalert@^2.1.2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/sweetalert/-/sweetalert-2.1.2.tgz#010baaa80d0dbdc86f96bfcaa96b490728594b79"
+  integrity sha512-iWx7X4anRBNDa/a+AdTmvAzQtkN1+s4j/JJRWlHpYE8Qimkohs8/XnFcWeYHH2lMA8LRCa5tj2d244If3S/hzA==
+  dependencies:
+    es6-object-assign "^1.1.0"
+    promise-polyfill "^6.0.2"
+
 term-size@^2.2.1:
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/term-size/-/term-size-2.2.1.tgz#2a6a54840432c2fb6320fea0f415531e90189f54"