diff --git a/dist/audio/music1.mp3 b/dist/audio/music1.mp3
new file mode 100644
index 0000000..4ae6c23
Binary files /dev/null and b/dist/audio/music1.mp3 differ
diff --git a/dist/audio/music2.mp3 b/dist/audio/music2.mp3
new file mode 100644
index 0000000..b1e99f1
Binary files /dev/null and b/dist/audio/music2.mp3 differ
diff --git a/js/assets.mjs b/js/assets.mjs
index 7b93028..ccabc99 100644
--- a/js/assets.mjs
+++ b/js/assets.mjs
@@ -39,7 +39,8 @@ export const audio = {
 	fuelPickup: 'blip2.mp3',
 	endEdit: 'release1.mp3',
 	newPlanet: 'up2.mp3',
-	engine: 'rocket2.ogg'
+	engine: 'rocket2.ogg',
+	music: 'music2.mp3'
 };
 
 export async function init() {
diff --git a/js/game/audio.mjs b/js/game/audio.mjs
index 473bf45..d103671 100644
--- a/js/game/audio.mjs
+++ b/js/game/audio.mjs
@@ -16,8 +16,20 @@ export function start(name) {
 }
 
 export function stop(name) {
-	if (!playing.has(name)) return;
+	if (!playing.has(name)) return false;
 	let howl = playing.get(name);
-	if (howl.playing())
+	if (howl.playing()) {
 		howl.stop();
+		return true;
+	}
+	return false;
+}
+
+export function toggle(name) {
+	if (!stop(name)) start(name);
+}
+
+export function volume(name, level) {
+	if (!playing.has(name)) return;
+	playing.get(name).volume(level);
 }
diff --git a/js/game/control.mjs b/js/game/control.mjs
index 6033390..53411e6 100644
--- a/js/game/control.mjs
+++ b/js/game/control.mjs
@@ -14,7 +14,8 @@ export const mapping = {
 	inventory: 'KeyE',
 	cycleRotation: 'KeyC',
 	toggleTrace: 'KeyT',
-	toggleMarkers: 'KeyR'
+	toggleMarkers: 'KeyR',
+	toggleMusic: 'KeyM'
 };
 
 let held, pressed;
@@ -34,11 +35,17 @@ export function tick() {
 			graphics.changeZoom(-input.mouse.scroll);
 		}
 	}
+
+	if (pressed[mapping.toggleMusic]) {
+		audio.toggle('music');
+	}
 }
 
 function tickPlaying() {
 	if (held[mapping.thrust]) {
 		playerShip.applyThrust({ forward: 1 });
+		let vol = Math.min(0.7, graphics.perspective.zoom / 10);
+		audio.volume('engine', vol);
 	} else {
 		audio.stop('engine');
 	}
diff --git a/js/game/edit.mjs b/js/game/edit.mjs
index 454540b..66e497f 100644
--- a/js/game/edit.mjs
+++ b/js/game/edit.mjs
@@ -91,8 +91,9 @@ function getAttributes() {
 
 	info = 'Mass: ' + mass + '\n' +
 		'Fuel capacity: ' + fuel + '\n' +
-		'Thrust/mass ratio: ' + (thrust / mass).toFixed(1) + '\n' +
-		'Rotation speed: ' + (rotation / mass * 100).toFixed(1) + '\n' +
+		'Thrust/mass ratio: ' + (thrust / Math.max(mass, 1)).toFixed(1) + '\n' +
+		'Rotation speed: ' + (rotation / Math.max(mass, 1) * 100).toFixed(1)
+			+ '\n' +
 		'Cargo capacity: ' + cargo;
 }
 
diff --git a/js/game/events.mjs b/js/game/events.mjs
index e4e7bb7..45457b5 100644
--- a/js/game/events.mjs
+++ b/js/game/events.mjs
@@ -15,6 +15,15 @@ let notLife = 0;
 
 let landedPlanets = new Set();
 
+export function playMusic() {
+	audio.start('music');
+	audio.volume('music', 0.8);
+}
+
+export function stopMusic() {
+	audio.stop('music');
+}
+
 function notify(message, time = 80) {
 	if (notification === null) return;
 	notification.text = message;
@@ -44,6 +53,10 @@ export function landShip(planet) {
 	game.state.landed = true;
 }
 
+export function howToPlay() {
+	game.state.controls = true;
+}
+
 function newPlanet(planet) {
 	let value = (planet.radius * 2 + 50) | 0;
 	landedPlanets.add(planet);
@@ -70,7 +83,6 @@ export function toggleEdit() {
 export function toggleTrace() {
 	let trace = graphics.toggleTrace();
 	notify('Path prediction: ' + (trace ? 'on' : 'off'));
-	audio.start('engine');
 }
 
 export function toggleMarkers() {
diff --git a/js/game/index.mjs b/js/game/index.mjs
index 966493b..db1cf98 100644
--- a/js/game/index.mjs
+++ b/js/game/index.mjs
@@ -24,7 +24,8 @@ export async function init() {
 	gui.init();
 	input.init();
 
-	//events.startGame();
+	//events.playMusic();
+	events.startGame();
 
 	//tick(); return;
 
diff --git a/js/graphics/index.mjs b/js/graphics/index.mjs
index 9b0042c..9db6106 100644
--- a/js/graphics/index.mjs
+++ b/js/graphics/index.mjs
@@ -108,6 +108,7 @@ class Perspective {
 		this.oldZoom = 0;
 		this.transition = 0;
 		this.zoomTransition = 0;
+		this.zoomTransitionSpeed = 0.9;
 		this.reset();
 	}
 
@@ -122,10 +123,11 @@ class Perspective {
 		[this.shiftX, this.shiftY] = [x, y];
 	}
 
-	changeZoom(zoom) {
+	changeZoom(zoom, speed = 0.9) {
 		this.oldZoom = this.currentZoom;
 		this.targetZoom = zoom;
 		this.zoomTransition = 1;
+		this.zoomTransitionSpeed = speed;
 	}
 
 	get currentShift() {
@@ -182,7 +184,7 @@ class Perspective {
 		this.zoom = this.currentZoom;
 
 		this.transition *= 0.9;
-		this.zoomTransition *= 0.9;
+		this.zoomTransition *= this.zoomTransitionSpeed;
 	}
 
 	reset() {
@@ -201,7 +203,8 @@ class Perspective {
 
 	zoomDelta(delta) {
 		let factor = 1 + (consts.ZOOM_SPEED * Math.abs(delta));
-		this.targetZoom *= delta > 0 ? factor : 1 / factor;
+		let target = this.targetZoom * (delta > 0 ? factor : 1 / factor);
+		this.changeZoom(target, 0.7);
 		this.normalize();
 	}
 
diff --git a/js/graphics/world.mjs b/js/graphics/world.mjs
index 3b20687..78b5758 100644
--- a/js/graphics/world.mjs
+++ b/js/graphics/world.mjs
@@ -28,8 +28,9 @@ function renderParticle(particle) {
 function renderEntity(entity) {
 	context.save();
 	context.translate(...entity.com);
-	if (graphics.perspective.zoom < 2 && graphics.markers) {
-		context.globalAlpha = 0.7 / graphics.perspective.zoom;
+	let alpha = Math.max(1 - ((graphics.perspective.zoom - 1) / 2), 0) ** 2;
+	if (alpha > 0 && graphics.markers) {
+		context.globalAlpha = alpha;
 		context.beginPath();
 		context.arc(0, 0, 4, 0, 2 * Math.PI);
 		context.lineWidth = 1;
diff --git a/js/gui/modules.mjs b/js/gui/modules.mjs
index 8f40ba9..37ecc3b 100644
--- a/js/gui/modules.mjs
+++ b/js/gui/modules.mjs
@@ -29,13 +29,20 @@ export function title() {
 	let startFunction = events.startGame;
 	let start = new GuiButton('Start game', events.startGame, 0, 0, 200);
 	shadow.append(start);
-	start.posRelative({ x: 0.5, xc: 0.5, y: 0.7 });
+	start.posRelative({ x: 0.5, xc: 0.5, y: 1 });
+	start.y -= 160;
 
 	let secondFunction = () => {};
 	let second = new GuiButton('Don\'t start game', secondFunction, 0, 0, 200);
 	shadow.append(second);
-	second.posRelative({ x: 0.5, xc: 0.5, y: 0.7 });
-	second.y += 60;
+	second.posRelative({ x: 0.5, xc: 0.5, y: 1 });
+	second.y -= 110;
+
+	let thirdFunction = events.howToPlay;
+	let third = new GuiButton('How to play', thirdFunction, 0, 0, 200);
+	shadow.append(third);
+	third.posRelative({ x: 0.5, xc: 0.5, y: 1 });
+	third.y -= 60;
 
 	return shadow;
 }
diff --git a/js/world/index.mjs b/js/world/index.mjs
index 7e7aa4e..bb95857 100644
--- a/js/world/index.mjs
+++ b/js/world/index.mjs
@@ -25,6 +25,11 @@ export function init() {
 	spawn.tick();
 }
 
+export function remove(object) {
+	entities.delete(object);
+	celestials.delete(object);
+}
+
 export function tick() {
 	particles.forEach(p => p.tick());
 	celestials.forEach(c => c.tick());
diff --git a/js/world/ship.mjs b/js/world/ship.mjs
index 4ad831a..1aa5a30 100644
--- a/js/world/ship.mjs
+++ b/js/world/ship.mjs
@@ -103,6 +103,7 @@ export default class Ship extends Body {
 		this.maxFuel = 0;
 		this.rotationPower = 0;
 		this.cargoCapacity = 0;
+		this.thrust = 0;
 
 		this.modules.forEach(m => {
 			if (m.type === 'fuel') {
diff --git a/js/world/spawn.mjs b/js/world/spawn.mjs
index 9af7dd0..f1c244d 100644
--- a/js/world/spawn.mjs
+++ b/js/world/spawn.mjs
@@ -8,7 +8,7 @@ import * as world from './index.mjs';
 import * as consts from '../consts.mjs';
 import {SECTOR_SIZE as SS} from '../consts.mjs';
 
-let spawnedSectors = new Set();
+let spawnedSectors = new Map();
 
 const visibleRadius = (400 / consts.MIN_ZOOM) + SS;
 
@@ -21,6 +21,16 @@ export function tick() {
 		let id = `${sx}.${sy}`;
 		if (!spawnedSectors.has(id)) spawnSector(sx, sy);
 	}
+
+	spawnedSectors.forEach((objects, key) => {
+		let [sx, sy] = key.split('.');
+		let [wx, wy] = [sx * SS, sy * SS];
+		let dis = (wx - px) ** 2 + (wy - py) ** 2;
+		if (dis > (SS * 4) ** 2) {
+			spawnedSectors.delete(key);
+			objects.forEach(world.remove);
+		}
+	});
 }
 
 function nearest(x, y, set) {
@@ -40,17 +50,18 @@ function nearest(x, y, set) {
 
 function spawnSector(x, y) {
 	let area = SS ** 2;
+	let spawned = new Set();
 
 	for (let i = 0; i < area / 1000; i++) {
 		let [px, py] = [(x + Math.random()) * SS, (y + Math.random()) * SS];
 		if (Math.random() < consts.PLANET_SPAWN_RATE / 1000) {
-			randomPlanet(px, py);
+			spawned.add(randomPlanet(px, py));
 		} else if (Math.random() < consts.ENTITY_SPAWN_RATE / 1000){
-			randomEntity(px, py);
+			spawned.add(randomEntity(px, py));
 		}
 	}
 
-	spawnedSectors.add(`${x}.${y}`);
+	spawnedSectors.set(`${x}.${y}`, spawned);
 }
 
 function randomPlanet(x, y, {