diff --git a/pages/index.js b/pages/index.js
index de83024..2b62d72 100644
--- a/pages/index.js
+++ b/pages/index.js
@@ -1,10 +1,10 @@
 import dynamic from "next/dynamic";
-import { useEffect, useState, useRef } from "react";
+import { useEffect, useState, useRef, useCallback } from "react";
 import styles from "../styles/Snake.module.css";
 
 const Config = {
-  height: 25,
-  width: 25,
+  height: 15,
+  width: 15,
   cellSize: 32,
 };
 
@@ -12,6 +12,7 @@ const CellType = {
   Snake: "snake",
   Food: "food",
   Empty: "empty",
+  Poison: "poison",
 };
 
 const Direction = {
@@ -21,7 +22,7 @@ const Direction = {
   Bottom: { x: 0, y: 1 },
 };
 
-const Cell = ({ x, y, type }) => {
+const Cell = ({ x, y, type, remaining }) => {
   const getStyles = () => {
     switch (type) {
       case CellType.Snake:
@@ -33,10 +34,20 @@ const Cell = ({ x, y, type }) => {
 
       case CellType.Food:
         return {
-          backgroundColor: "darkorange",
+          backgroundColor: "tomato",
           borderRadius: 20,
           width: 32,
           height: 32,
+          transform: `scale(${0.5 + remaining / 20})`,
+        };
+
+      case CellType.Poison:
+        return {
+          backgroundColor: "red",
+          borderRadius: 20,
+          width: 32,
+          height: 32,
+          transform: `scale(${0.5 + remaining / 20})`,
         };
 
       default:
@@ -53,89 +64,172 @@ const Cell = ({ x, y, type }) => {
         height: Config.cellSize,
       }}
     >
-      <div className={styles.cell} style={getStyles()}></div>
+      <div className={styles.cell} style={getStyles()}>
+        {remaining}
+      </div>
     </div>
   );
 };
 
-const getRandomCell = () => ({
+const getRandomCell = (type) => ({
   x: Math.floor(Math.random() * Config.width),
   y: Math.floor(Math.random() * Config.width),
+  start: Date.now(),
+  type: type,
 });
 
-const Snake = () => {
+//custom hook
+//controller
+const useInterval = (func, dir) => {
+  const timer = useRef(Date.now());
+  const createCallback = useCallback(() => {
+    if (Date.now() - timer.current > dir) {
+      timer.current = Date.now();
+      func();
+    }
+  }, [dir, func]);
+
+  useEffect(() => {
+    const interval = setInterval(createCallback, 1000 / 60);
+    return () => clearInterval(interval);
+  }, [createCallback]);
+};
+const GetSnake = () => {
   const getDefaultSnake = () => [
     { x: 8, y: 12 },
     { x: 7, y: 12 },
     { x: 6, y: 12 },
   ];
-  const grid = useRef();
-
   // snake[0] is head and snake[snake.length - 1] is tail
   const [snake, setSnake] = useState(getDefaultSnake());
   const [direction, setDirection] = useState(Direction.Right);
+  const [objects, setObjects] = useState([]);
+  const score = snake.length - 3;
 
-  const [food, setFood] = useState({ x: 4, y: 10 });
-  const [score, setScore] = useState(0);
+  const finding = ({ x, y }, arr, type) => {
+    //for snake
+    if (type === undefined)
+      return arr.find((position) => position.x === x && position.y === y);
+    return arr.find(
+      (position) =>
+        position.x === x && position.y === y && position.type === type
+    );
+  };
 
-  // move the snake
-  useEffect(() => {
-    const runSingleStep = () => {
-      setSnake((snake) => {
-        const head = snake[0];
-        const newHead = { x: head.x + direction.x, y: head.y + direction.y };
+  //checking cells
+  const isObjectOrSnake = useCallback(
+    ({ x, y }, type) => {
+      if (type === CellType.Snake) return finding({ x, y }, snake);
+      else return finding({ x, y }, objects, type);
+    },
+    [objects, snake]
+  );
 
-        // make a new snake by extending head
-        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax
-        const newSnake = [newHead, ...snake];
+  //restart the game
+  const resetGame = useCallback(() => {
+    setSnake(getDefaultSnake());
+    setDirection(Direction.Right);
+    setObjects([]);
+  }, []);
 
-        // remove tail
-        newSnake.pop();
+  //moving the snake
+  const runSingleStep = useCallback(() => {
+    setSnake((snake) => {
+      const head = snake[0];
+      const newHead = {
+        x: (head.x + direction.x + Config.width) % Config.width,
+        y: (head.y + direction.y + Config.height) % Config.height,
+      };
 
-        return newSnake;
-      });
-    };
+      // make a new snake by extending head
+      const newSnake = [newHead, ...snake];
 
-    runSingleStep();
-    const timer = setInterval(runSingleStep, 500);
+      // remove tail when head doesnt eat food
+      if (!isObjectOrSnake(newHead, CellType.Food)) {
+        newSnake.pop();
+      }
+      //remove again when eats poison
+      if (isObjectOrSnake(newHead, CellType.Poison)) {
+        newSnake.pop();
+      }
+      if (isObjectOrSnake(newHead, CellType.Snake) || score < 0) {
+        resetGame();
+      }
 
-    return () => clearInterval(timer);
-  }, [direction, food]);
+      return newSnake;
+    });
+  }, [direction.x, direction.y, isObjectOrSnake, resetGame, score]);
 
-  // update score whenever head touches a food
-  useEffect(() => {
-    const head = snake[0];
-    if (isFood(head)) {
-      setScore((score) => {
-        return score + 1;
-      });
-
-      let newFood = getRandomCell();
-      while (isSnake(newFood)) {
-        newFood = getRandomCell();
+  const addObject = useCallback(
+    (type) => {
+      let newObject = getRandomCell(type);
+      while (
+        isObjectOrSnake(
+          newObject,
+          CellType.Snake ||
+            isObjectOrSnake(newObject, CellType.Food) ||
+            isObjectOrSnake(isObjectOrSnake, CellType.Poison)
+        )
+      ) {
+        newObject = getRandomCell(type);
       }
+      console.log(newObject.type);
+      setObjects((currentObjects) => [...currentObjects, newObject]);
+    },
+    [isObjectOrSnake]
+  );
+  const removeObject = useCallback(() => {
+    setObjects((currentObjects) =>
+      currentObjects.filter(
+        (currentObject) => Date.now() - currentObject.start < 10000
+      )
+    );
+  }, []);
 
-      setFood(newFood);
+  // update foods and poisons whenever head touches a food or a poison
+  useEffect(() => {
+    const head = snake[0];
+    if (isObjectOrSnake(head, CellType.Food)) {
+      console.log("ate food");
+      setObjects((currentObjects) =>
+        currentObjects.filter(
+          (currentObject) =>
+            !(currentObject.x === head.x && currentObject.y === head.y)
+        )
+      );
     }
-  }, [snake]);
+  }, [isObjectOrSnake, snake]);
+
+  useInterval(() => addObject(CellType.Food), 3000);
+  useInterval(() => addObject(CellType.Poison), 1000);
+  useInterval(runSingleStep, 300);
+  useInterval(() => removeObject(), 50);
+  useInterval(() => removeObject(), 100);
+
+  const changeDir = (checkDir, newDir) => {
+    setDirection((direction) => {
+      if (direction != checkDir) return newDir;
+      return direction;
+    });
+  };
 
   useEffect(() => {
     const handleNavigation = (event) => {
       switch (event.key) {
         case "ArrowUp":
-          setDirection(Direction.Top);
+          changeDir(Direction.Bottom, Direction.Top);
           break;
 
         case "ArrowDown":
-          setDirection(Direction.Bottom);
+          changeDir(Direction.Top, Direction.Bottom);
           break;
 
         case "ArrowLeft":
-          setDirection(Direction.Left);
+          changeDir(Direction.Right, Direction.Left);
           break;
 
         case "ArrowRight":
-          setDirection(Direction.Right);
+          changeDir(Direction.Left, Direction.Right);
           break;
       }
     };
@@ -143,27 +237,39 @@ const Snake = () => {
 
     return () => window.removeEventListener("keydown", handleNavigation);
   }, []);
-
-  // ?. is called optional chaining
-  // see: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining
-  const isFood = ({ x, y }) => food?.x === x && food?.y === y;
-
-  const isSnake = ({ x, y }) =>
-    snake.find((position) => position.x === x && position.y === y);
-
   const cells = [];
   for (let x = 0; x < Config.width; x++) {
     for (let y = 0; y < Config.height; y++) {
-      let type = CellType.Empty;
-      if (isFood({ x, y })) {
+      let type = CellType.Empty,
+        remaining = undefined;
+      if (isObjectOrSnake({ x, y }, CellType.Food)) {
         type = CellType.Food;
-      } else if (isSnake({ x, y })) {
+        remaining =
+          10 -
+          Math.round(
+            (Date.now() - finding({ x, y }, objects, type).start) / 1000
+          );
+      } else if (isObjectOrSnake({ x, y }, CellType.Snake)) {
         type = CellType.Snake;
+      } else if (isObjectOrSnake({ x, y }, CellType.Poison)) {
+        type = CellType.Poison;
+        remaining =
+          10 -
+          Math.round(
+            (Date.now() - finding({ x, y }, objects, type).start) / 1000
+          );
       }
-      cells.push(<Cell key={`${x}-${y}`} x={x} y={y} type={type} />);
+      cells.push(
+        <Cell key={`${x}-${y}`} x={x} y={y} type={type} remaining={remaining} />
+      );
     }
   }
+  return { score, isObjectOrSnake, cells };
+};
 
+//view
+const Snake = () => {
+  const { score, cells } = GetSnake();
   return (
     <div className={styles.container}>
       <div
diff --git a/styles/Snake.module.css b/styles/Snake.module.css
index b4f0f28..e9b527a 100644
--- a/styles/Snake.module.css
+++ b/styles/Snake.module.css
@@ -34,4 +34,8 @@
 .cell {
   width: 100%;
   height: 100%;
-}
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  color: white;
+}
\ No newline at end of file