diff --git a/game.js b/game.js
index 0fb7bfe..8d4d3e2 100644
--- a/game.js
+++ b/game.js
@@ -81,6 +81,8 @@ const vertexShader = `
 `;
 
 const diameterOfTunnel = 100;
+const spawnInterval = 40;
+let lastSpawned = 0;
 
 var gn;
 var headSet = false;
@@ -193,7 +195,7 @@ init_gn();
 
 import * as THREE from './three.module.js';
 let scene, renderer;
-const camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.1, 1000);
+const camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.1, 10000);
 
 const geometrySphere = new THREE.SphereGeometry(11, 32, 32);
 const materialCube = new THREE.MeshBasicMaterial();
@@ -318,7 +320,7 @@ function animate() {
 	if (running) {
 
 		for (let i = 0; i < cubes.length; i++) {
-			if (cubes[i].geometry.parameters.radius !== geometrySphere.parameters.radius) {
+			if (cubes[i].material !== materialCube) {
 				continue;
 			}
 			let x1 = cubes[i].position.x;
@@ -333,7 +335,7 @@ function animate() {
 				z2 = Math.max(z1, z2 - speed);
 			}
 			let dist_squared = (x1 - x2) ** 2 + (y1 - y2) ** 2 + (z1 - z2) ** 2;
-			if (dist_squared <= cubes[i].geometry.parameters.radius ** 2) {
+			if (dist_squared <= (cubes[i].geometry.parameters.radius * cubes[i].scale.x) ** 2) {
 				gameOver();
 				break;
 			}
@@ -344,14 +346,20 @@ function animate() {
 		camera.position.x += 0.1 * leftRightMove;
 		camera.position.y += 0.1 * upDownMove;
 
-		if (Math.random() < 0.09) {
+		while (camera.position.z < lastSpawned - spawnInterval) {
+			lastSpawned -= spawnInterval;
+
+			// randomly spawn large spheres
+			let scale = Math.random() < 0.1 ? 5.0 : 1.0;
+
 			const meshCube = new THREE.Mesh(geometrySphere, materialCube);
-			meshCube.position.z = camera.position.z - 930;
+			meshCube.position.z = camera.position.z - speed * 210;
 			meshCube.position.x = (2 * Math.random() - 1.0) * diameterOfTunnel;
 			meshCube.position.y = (2 * Math.random() - 1.0) * 0.9 * diameterOfTunnel;
+			meshCube.scale.multiplyScalar(scale);
 
 			const outlineMesh = new THREE.Mesh(geometrySphere, customMaterial);
-			outlineMesh.scale.multiplyScalar(1.17);
+			outlineMesh.scale.multiplyScalar(scale * 1.17);
 			outlineMesh.position.z = meshCube.position.z;
 			outlineMesh.position.x = meshCube.position.x;
 			outlineMesh.position.y = meshCube.position.y;
@@ -368,7 +376,7 @@ function animate() {
 
 
 	for (let i = 0; i < cubes.length; i++) {
-		if (cubes[i].position.z > camera.position.z + cubes[i].geometry.parameters.radius) {
+		if (cubes[i].position.z > camera.position.z + cubes[i].geometry.parameters.radius * cubes[i].scale.x) {
 			scene.remove(cubes[i]);
 			cubes.splice(i, 1);
 			i--;
@@ -380,7 +388,7 @@ function animate() {
 		removed = removed % 2;
 		document.getElementById("score").innerText = score;
 	}
-	if (borders.length == 0 || borders[borders.length - 1].position.z - camera.position.z > -600) {
+	if (borders.length == 0 || borders[borders.length - 1].position.z - camera.position.z > -1200) {
 		const newZ = borders.length == 0 ? -200 : borders[borders.length - 1].position.z - diameterOfTunnel * 2;
 
 		let border = new THREE.Mesh(borderGeometry, material);