diff --git a/app/play/[level]/page.tsx b/app/play/[level]/page.tsx
index 61c6b0d..f551949 100644
--- a/app/play/[level]/page.tsx
+++ b/app/play/[level]/page.tsx
@@ -10,6 +10,7 @@ import { Map } from "@/components/Map";
 import { Page, PageTitle } from "@/components/Page";
 import { Visualizer } from "@/components/Visualizer";
 import { Button } from "@/components/ui/button";
+import { Slider } from "@/components/ui/slider";
 import {
   Table,
   TableBody,
@@ -19,6 +20,7 @@ import {
   TableRow,
 } from "@/components/ui/table";
 import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
+import { DEFAULT_REPLAY_SPEED } from "@/constants/visualizer";
 import { api } from "@/convex/_generated/api";
 import { ZombieSurvival } from "@/simulators/zombie-survival";
 
@@ -39,6 +41,7 @@ export default function PlayLevelPage({
   const [landmineCount, setLandmineCount] = useState(0);
   const flags = useQuery(api.flags.getFlags);
   const [mode, setMode] = useState<"play" | "test">("play");
+  const [replaySpeed, setReplaySpeed] = useState(DEFAULT_REPLAY_SPEED);
 
   // Initialize playerMap when map data is available
   useEffect(() => {
@@ -242,6 +245,7 @@ export default function PlayLevelPage({
                       autoStart
                       onReset={handleReset}
                       onSimulationEnd={handleSimulationEnd}
+                      replaySpeed={replaySpeed}
                     />
                     {gameResult && (
                       <div
@@ -274,19 +278,34 @@ export default function PlayLevelPage({
                   </div>
                 )}
               </div>
-              <div className="flex justify-center gap-4">
+              <div className="flex flex-col items-center justify-center gap-4">
                 {!isSimulating ? (
                   <>
-                    <Button onClick={runSimulation} className="h-10">
-                      Run Simulation
-                    </Button>
-                    <Button
-                      onClick={handleClearMap}
-                      variant="outline"
-                      className="h-10"
-                    >
-                      Clear Map
-                    </Button>
+                    <div className="flex flex-col items-center gap-2">
+                      <h3>Choose the speed (200ms to 2s)</h3>
+                      <Slider
+                        className="w-2/3"
+                        defaultValue={[DEFAULT_REPLAY_SPEED]}
+                        min={200}
+                        max={2000}
+                        step={100}
+                        onValueChange={(value) => {
+                          setReplaySpeed(value[0]);
+                        }}
+                      />
+                    </div>
+                    <div className="flex justify-center gap-4">
+                      <Button onClick={runSimulation} className="h-10">
+                        Run Simulation
+                      </Button>
+                      <Button
+                        onClick={handleClearMap}
+                        variant="outline"
+                        className="h-10"
+                      >
+                        Clear Map
+                      </Button>
+                    </div>
                   </>
                 ) : (
                   <div className="flex items-center gap-x-3">
diff --git a/components/Visualizer.tsx b/components/Visualizer.tsx
index 0c9a8e0..5ee18d0 100644
--- a/components/Visualizer.tsx
+++ b/components/Visualizer.tsx
@@ -1,6 +1,9 @@
 import * as React from "react";
 import { Button } from "@/components/ui/button";
-import { AUTO_REPLAY_SPEED, REPLAY_SPEED } from "@/constants/visualizer";
+import {
+  AUTO_REPLAY_SPEED,
+  DEFAULT_REPLAY_SPEED,
+} from "@/constants/visualizer";
 import { Renderer } from "@/renderer";
 import { ZombieSurvival } from "@/simulators/zombie-survival";
 
@@ -12,6 +15,7 @@ export function Visualizer({
   map,
   onReset,
   onSimulationEnd,
+  replaySpeed = DEFAULT_REPLAY_SPEED,
 }: {
   autoReplay?: boolean;
   autoStart?: boolean;
@@ -20,6 +24,7 @@ export function Visualizer({
   map: string[][];
   onReset?: () => unknown;
   onSimulationEnd?: (isWin: boolean) => unknown;
+  replaySpeed?: number;
 }) {
   const simulator = React.useRef<ZombieSurvival>(new ZombieSurvival(map));
   const renderer = React.useRef<Renderer | null>(null);
@@ -79,7 +84,7 @@ export function Visualizer({
       if (onSimulationEnd) {
         onSimulationEnd(!simulator.current.getPlayer().dead());
       }
-    }, REPLAY_SPEED);
+    }, replaySpeed);
   }
 
   React.useEffect(() => {
diff --git a/components/ui/slider.tsx b/components/ui/slider.tsx
new file mode 100644
index 0000000..ab19d57
--- /dev/null
+++ b/components/ui/slider.tsx
@@ -0,0 +1,28 @@
+"use client"
+
+import * as React from "react"
+import * as SliderPrimitive from "@radix-ui/react-slider"
+
+import { cn } from "@/lib/utils"
+
+const Slider = React.forwardRef<
+  React.ElementRef<typeof SliderPrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof SliderPrimitive.Root>
+>(({ className, ...props }, ref) => (
+  <SliderPrimitive.Root
+    ref={ref}
+    className={cn(
+      "relative flex w-full touch-none select-none items-center",
+      className
+    )}
+    {...props}
+  >
+    <SliderPrimitive.Track className="relative h-1.5 w-full grow overflow-hidden rounded-full bg-primary/20">
+      <SliderPrimitive.Range className="absolute h-full bg-primary" />
+    </SliderPrimitive.Track>
+    <SliderPrimitive.Thumb className="block h-4 w-4 rounded-full border border-primary/50 bg-background shadow transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50" />
+  </SliderPrimitive.Root>
+))
+Slider.displayName = SliderPrimitive.Root.displayName
+
+export { Slider }
diff --git a/constants/visualizer.ts b/constants/visualizer.ts
index c5083b4..653687c 100644
--- a/constants/visualizer.ts
+++ b/constants/visualizer.ts
@@ -1,2 +1,2 @@
 export const AUTO_REPLAY_SPEED = 1_500;
-export const REPLAY_SPEED = 600;
+export const DEFAULT_REPLAY_SPEED = 600;
diff --git a/package.json b/package.json
index 58301a0..3e028c7 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
     "@radix-ui/react-dropdown-menu": "^2.1.1",
     "@radix-ui/react-icons": "^1.3.0",
     "@radix-ui/react-select": "^2.1.2",
+    "@radix-ui/react-slider": "^1.2.1",
     "@radix-ui/react-slot": "^1.1.0",
     "@radix-ui/react-tabs": "^1.1.1",
     "@radix-ui/react-toast": "^1.2.1",
diff --git a/renderer/Renderer.ts b/renderer/Renderer.ts
index 3632f66..eb1008d 100644
--- a/renderer/Renderer.ts
+++ b/renderer/Renderer.ts
@@ -2,7 +2,7 @@ import { assets, loadAssets } from "./Assets";
 import * as Canvas from "./Canvas";
 import { type RendererEffect, RendererEffectType } from "./Effect";
 import { RendererItem } from "./Item";
-import { REPLAY_SPEED } from "@/constants/visualizer";
+import { DEFAULT_REPLAY_SPEED } from "@/constants/visualizer";
 import {
   type Entity,
   EntityType,
@@ -272,7 +272,7 @@ export class Renderer {
 
       const positionToEffect: RendererEffect = {
         type: RendererEffectType.PositionTo,
-        duration: REPLAY_SPEED,
+        duration: DEFAULT_REPLAY_SPEED,
         startedAt: Date.now(),
         to: {
           x: to.x * this.cellSize,