diff --git a/app/play/[level]/page.tsx b/app/play/[level]/page.tsx
index cdb183f..2078ce4 100644
--- a/app/play/[level]/page.tsx
+++ b/app/play/[level]/page.tsx
@@ -11,6 +11,7 @@ import { ChevronLeftIcon } from "@radix-ui/react-icons";
 import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import TestMode from "./test-mode";
 import { useRouter } from "next/navigation";
+import { ZombieSurvival } from "@/simulators/zombie-survival";
 
 export default function PlayLevelPage({
   params,
@@ -119,7 +120,7 @@ export default function PlayLevelPage({
   };
 
   const runSimulation = () => {
-    if (!playerMap.some((row) => row.includes("P"))) {
+    if (!ZombieSurvival.mapHasPlayer(playerMap)) {
       alert(
         "Please place a player (P) on the map before running the simulation.",
       );
@@ -140,6 +141,11 @@ export default function PlayLevelPage({
     }
   };
 
+  const handleReset = () => {
+    setIsSimulating(false);
+    setGameResult(null);
+  };
+
   const handleClearMap = () => {
     setPlayerMap(map.grid.map((row) => [...row]));
     setBlockCount(0);
@@ -195,6 +201,7 @@ export default function PlayLevelPage({
                 <Visualizer
                   map={playerMap}
                   autoStart={true}
+                  onReset={handleReset}
                   onSimulationEnd={handleSimulationEnd}
                 />
                 {gameResult && (
diff --git a/components/Visualizer.tsx b/components/Visualizer.tsx
index fc144a7..4f8bcef 100644
--- a/components/Visualizer.tsx
+++ b/components/Visualizer.tsx
@@ -13,6 +13,7 @@ export function Visualizer({
   controls = true,
   cellSize = "64",
   map,
+  onReset,
   onSimulationEnd,
 }: {
   autoReplay?: boolean;
@@ -20,6 +21,7 @@ export function Visualizer({
   controls?: boolean;
   cellSize?: string;
   map: string[][];
+  onReset?: () => unknown;
   onSimulationEnd?: (isWin: boolean) => unknown;
 }) {
   const visualizer = useVisualizer();
@@ -54,6 +56,7 @@ export function Visualizer({
 
   function startSimulation() {
     simulator.current = new ZombieSurvival(map);
+    renderer.current?.render(simulator.current.getAllAliveEntities());
     setRunning(true);
 
     interval.current = setInterval(() => {
@@ -63,11 +66,7 @@ export function Visualizer({
 
       if (!simulator.current.finished()) {
         simulator.current.step();
-
-        if (renderer.current !== null) {
-          renderer.current.render(simulator.current.getAllAliveEntities());
-        }
-
+        renderer.current?.render(simulator.current.getAllAliveEntities());
         return;
       }
 
@@ -133,13 +132,7 @@ export function Visualizer({
             <Button onClick={startSimulation} disabled={running}>
               Replay
             </Button>
-            <Button
-              disabled={running}
-              onClick={() => {
-                simulator.current = new ZombieSurvival(map);
-                setRunning(false);
-              }}
-            >
+            <Button disabled={running} onClick={onReset}>
               Reset
             </Button>
           </div>