Update #2

Script.js

@@ -143,8 +143,6 @@ function gameLoop(timestamp) {
 function keyDownPressed(e) {
   if (e.keyCode == 87) {
     keys.up = true;
-    backgroundMusic.play();
-    backgroundMusic.volume = 0.8;
   } else if (e.keyCode == 83) {
     keys.down = true;
   }
@@ -507,19 +505,24 @@ function drawGameOver() {
 }
 
 function crossfadeToGameOver() {
-    let fadeSpeed = 0.02; // smaller = slower fade
+    let fadeSpeed = 0.02;
+
     gameOverBGM.volume = 0;
     gameOverBGM.play();
 
     let fadeInterval = setInterval(() => {
-        currentBGM.volume -= fadeSpeed;
-        gameOverBGM.volume += fadeSpeed;
 
-        if (currentBGM.volume <= 0) {
+        currentBGM.volume -= fadeSpeed;
+        if (currentBGM.volume < 0) currentBGM.volume = 0;
+
+        gameOverBGM.volume += fadeSpeed;
+        if (gameOverBGM.volume > 1) gameOverBGM.volume = 1;
+
+        if (currentBGM.volume === 0) {
             currentBGM.pause();
-            currentBGM.volume = 1;
             clearInterval(fadeInterval);
         }
-    }, 1000 / 30); // 30 updates per second
+
+    }, 1000 / 30);
 }