diff --git a/app/build/intermediates/res/resources-debug.ap_ b/app/build/intermediates/res/resources-debug.ap_
index 76644bc..ea0e827 100644
Binary files a/app/build/intermediates/res/resources-debug.ap_ and b/app/build/intermediates/res/resources-debug.ap_ differ
diff --git a/app/src/main/java/com/example/julian/endlessroll/data/SynchronizedArrayList.java b/app/src/main/java/com/example/julian/endlessroll/data/SynchronizedArrayList.java
new file mode 100644
index 0000000..6bf3065
--- /dev/null
+++ b/app/src/main/java/com/example/julian/endlessroll/data/SynchronizedArrayList.java
@@ -0,0 +1,147 @@
+package com.example.julian.endlessroll.data;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+/**
+ * Created by Julian on 16.11.2016.
+ */
+
+public class SynchronizedArrayList<E> extends ArrayList<E> {
+
+    @Override
+    public synchronized String toString() {
+        return super.toString();
+    }
+
+    @Override
+    public synchronized boolean add(E object) {
+        return super.add(object);
+    }
+
+    @Override
+    public synchronized void add(int index, E object) {
+        super.add(index, object);
+    }
+
+    @Override
+    public synchronized boolean addAll(Collection<? extends E> collection) {
+        return super.addAll(collection);
+    }
+
+    @Override
+    public synchronized boolean addAll(int index, Collection<? extends E> collection) {
+        return super.addAll(index, collection);
+    }
+
+    @Override
+    public synchronized void clear() {
+        super.clear();
+    }
+
+    @Override
+    public synchronized Object clone() {
+        return super.clone();
+    }
+
+    @Override
+    public synchronized void ensureCapacity(int minimumCapacity) {
+        super.ensureCapacity(minimumCapacity);
+    }
+
+    @Override
+    public synchronized E get(int index) {
+        return super.get(index);
+    }
+
+    @Override
+    public synchronized int size() {
+        return super.size();
+    }
+
+    @Override
+    public synchronized boolean isEmpty() {
+        return super.isEmpty();
+    }
+
+    @Override
+    public synchronized boolean contains(Object object) {
+        return super.contains(object);
+    }
+
+    @Override
+    public synchronized int indexOf(Object object) {
+        return super.indexOf(object);
+    }
+
+    @Override
+    public synchronized int lastIndexOf(Object object) {
+        return super.lastIndexOf(object);
+    }
+
+    @Override
+    public synchronized E remove(int index) {
+        return super.remove(index);
+    }
+
+    @Override
+    public synchronized boolean remove(Object object) {
+        return super.remove(object);
+    }
+
+    @Override
+    protected synchronized void removeRange(int fromIndex, int toIndex) {
+        super.removeRange(fromIndex, toIndex);
+    }
+
+    @Override
+    public synchronized E set(int index, E object) {
+        return super.set(index, object);
+    }
+
+    @Override
+    public synchronized Object[] toArray() {
+        return super.toArray();
+    }
+
+    @Override
+    public synchronized <T> T[] toArray(T[] contents) {
+        return super.toArray(contents);
+    }
+
+    @Override
+    public synchronized void trimToSize() {
+        super.trimToSize();
+    }
+
+    @Override
+    public synchronized int hashCode() {
+        return super.hashCode();
+    }
+
+    @Override
+    public synchronized boolean equals(Object o) {
+        return super.equals(o);
+    }
+
+    @Override
+    public synchronized List<E> subList(int start, int end) {
+        return super.subList(start, end);
+    }
+
+    @Override
+    public synchronized boolean containsAll(Collection<?> collection) {
+        return super.containsAll(collection);
+    }
+
+    @Override
+    public synchronized boolean removeAll(Collection<?> collection) {
+        return super.removeAll(collection);
+    }
+
+    @Override
+    public synchronized boolean retainAll(Collection<?> collection) {
+        return super.retainAll(collection);
+    }
+}
diff --git a/app/src/main/java/com/example/julian/endlessroll/entities/Background.java b/app/src/main/java/com/example/julian/endlessroll/entities/Background.java
index ca0c2ce..fc94d2d 100644
--- a/app/src/main/java/com/example/julian/endlessroll/entities/Background.java
+++ b/app/src/main/java/com/example/julian/endlessroll/entities/Background.java
@@ -1,14 +1,13 @@
 package com.example.julian.endlessroll.entities;
 
+import com.example.julian.endlessroll.data.SynchronizedArrayList;
 import com.example.julian.endlessroll.data.Vector;
 import com.example.julian.endlessroll.entities.textures.Texture;
 
-import java.util.ArrayList;
-
 /**
  * Created by Julian on 20.07.2016.
  */
-public class Background extends ArrayList<Entity> {
+public class Background extends SynchronizedArrayList<Entity> {
 
     private final float PART_WIDTH = 5;
     private final float HALF_PART_WIDTH = PART_WIDTH / 2;
@@ -21,8 +20,10 @@ public class Background extends ArrayList<Entity> {
 
     public void changeTexture(Texture texture) {
         this.texture = texture;
-        for (Entity entity : this)
-            entity.setTexture(texture);
+        synchronized (this) {
+            for (Entity entity : this)
+                entity.setTexture(texture);
+        }
     }
 
     private Entity createPart(float xLeftEdge) {
@@ -31,8 +32,10 @@ public class Background extends ArrayList<Entity> {
 
     public void move(float x, float cameraX) {
         Vector movement = new Vector(x, 0);
-        for (Entity part : this)
-            part.move(movement);
+        synchronized (this) {
+            for (Entity part : this)
+                part.move(movement);
+        }
         if (!super.isEmpty()) {
             Entity last = super.get(super.size() - 1);
             if (last.getRightEdge() - cameraX < 3) {
diff --git a/app/src/main/java/com/example/julian/endlessroll/entities/tileLists/TileList.java b/app/src/main/java/com/example/julian/endlessroll/entities/tileLists/TileList.java
index fedb0d4..9533d34 100644
--- a/app/src/main/java/com/example/julian/endlessroll/entities/tileLists/TileList.java
+++ b/app/src/main/java/com/example/julian/endlessroll/entities/tileLists/TileList.java
@@ -1,5 +1,6 @@
 package com.example.julian.endlessroll.entities.tileLists;
 
+import com.example.julian.endlessroll.data.SynchronizedArrayList;
 import com.example.julian.endlessroll.entities.Entity;
 import com.example.julian.endlessroll.entities.textures.Texture;
 import com.example.julian.endlessroll.levels.TileData;
@@ -9,7 +10,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 @SuppressWarnings("serial")
-public class TileList extends ArrayList<Tile> {
+public class TileList extends SynchronizedArrayList<Tile> {
 
     public enum Type {
         TERRAIN, CEILING;
diff --git a/app/src/main/java/com/example/julian/endlessroll/main/game/GameScene.java b/app/src/main/java/com/example/julian/endlessroll/main/game/GameScene.java
index 3496b23..13ba0e6 100644
--- a/app/src/main/java/com/example/julian/endlessroll/main/game/GameScene.java
+++ b/app/src/main/java/com/example/julian/endlessroll/main/game/GameScene.java
@@ -19,6 +19,7 @@ import com.example.julian.endlessroll.levels.worlds.World;
 import com.example.julian.endlessroll.main.GameLog;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
@@ -46,14 +47,12 @@ public class GameScene extends Scene {
     public void loadLevel(Level level, World world) throws Exception {
         this.currentWorld = world;
         reset();
-        lock.lock();
         background.changeTexture(world.getBackground());
         terrain.loadData(world, level.getTerrainEdge(), level.getTerrainTiles());
         ceiling.loadData(world, level.getCeilingEdge(), level.getCeilingTiles());
         super.add(goal);
         player.init(terrain.getEdge(), level.getStartSpeed(), level.getEndSpeed());
         super.add(player);
-        lock.unlock();
         for (ObstacleData data : level.getObstacles())
             addObstacle(data);
         for (StarData data : level.getStars()) {
@@ -71,9 +70,7 @@ public class GameScene extends Scene {
     }
 
     private void reset() {
-        lock.lock();
         super.clear();
-        lock.unlock();
         obstacles.clear();
         tools.clear();
         cameraX = 0;
@@ -81,7 +78,6 @@ public class GameScene extends Scene {
     }
 
     public void onStarCollision(Star collisionStar) {
-        lock.lock();
         Iterator<Star> iter = stars.iterator();
         while (iter.hasNext()) {
             Star star = iter.next();
@@ -90,24 +86,18 @@ public class GameScene extends Scene {
                 iter.remove();
             }
         }
-        lock.unlock();
-        //TODO: change lock with atomic lists!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     }
 
     public void addObstacle(ObstacleData data) {
         Obstacle obstacle = new Obstacle(currentWorld, data, terrain.getEdge());
-        lock.lock();
         super.add(obstacle);
         obstacles.add(obstacle);
-        lock.unlock();
     }
 
     public void addStar(StarData data) {
         Star star = new Star(textures.star, data);
-        lock.lock();
         super.add(star);
         stars.add(star);
-        lock.unlock();
     }
 
     public void addTool(ToolType type, float screenX, float screenY) throws Exception {
@@ -115,10 +105,8 @@ public class GameScene extends Scene {
         Tool tool = type.newInstance(position, particleSystem);
         if (tool == null)
             throw new Exception("Current ToolType(" + type + ") returns null at method newInstance()");
-        lock.lock();
         super.add(tool);
         tools.add(tool);
-        lock.unlock();
     }
 
 
@@ -126,7 +114,6 @@ public class GameScene extends Scene {
     public void update(Timer timer) {
         super.update(timer);
         player.setSpeedByProgress(player.getProgress() / goalX);
-        lock.lock();
         for (Tool tool : tools) {
             tool.update(timer);
             if (tool instanceof Bomb) {
@@ -135,7 +122,6 @@ public class GameScene extends Scene {
                     bomb.explode(obstacles, collisionDetector);
             }
         }
-        lock.unlock();
     }
 
     @Override
diff --git a/app/src/main/java/com/example/julian/endlessroll/main/game/Physics.java b/app/src/main/java/com/example/julian/endlessroll/main/game/Physics.java
index 6283719..b59f884 100644
--- a/app/src/main/java/com/example/julian/endlessroll/main/game/Physics.java
+++ b/app/src/main/java/com/example/julian/endlessroll/main/game/Physics.java
@@ -35,7 +35,6 @@ public class Physics {
     }
 
     public void applyGravity(GameScene scene) {
-        scene.lock.lock();
         scene.getPlayer().getMovement().y -= GRAVITY_FORCE;
         for (Tool tool : scene.getTools()) {
             if (tool.isFloating())
@@ -71,7 +70,6 @@ public class Physics {
                 tool.setToTerrain(orientingHeight);
             }
         }
-        scene.lock.unlock();
     }
 
     @Nullable
diff --git a/app/src/main/java/com/example/julian/endlessroll/main/game/Scene.java b/app/src/main/java/com/example/julian/endlessroll/main/game/Scene.java
index c81a9c7..12a04b7 100644
--- a/app/src/main/java/com/example/julian/endlessroll/main/game/Scene.java
+++ b/app/src/main/java/com/example/julian/endlessroll/main/game/Scene.java
@@ -1,5 +1,6 @@
 package com.example.julian.endlessroll.main.game;
 
+import com.example.julian.endlessroll.data.SynchronizedArrayList;
 import com.example.julian.endlessroll.data.Vector;
 import com.example.julian.endlessroll.entities.Background;
 import com.example.julian.endlessroll.entities.Entity;
@@ -11,16 +12,14 @@ import com.example.julian.endlessroll.entities.tileLists.Terrain;
 import com.example.julian.endlessroll.levels.worlds.World;
 import com.example.julian.endlessroll.rendering.Lock;
 
-import java.util.ArrayList;
 import java.util.Iterator;
 
 /**
  * Created by Julian on 20.07.2016.
  */
-public abstract class Scene extends ArrayList<Entity> {
+public abstract class Scene extends SynchronizedArrayList<Entity> {
 
     public float cameraX;
-    public final Lock lock;
 
     private Vector screenSize;
     private Entity playerArrow;
@@ -40,7 +39,6 @@ public abstract class Scene extends ArrayList<Entity> {
         terrain = new Terrain(World.GRASSLANDS.getTerrain());
         ceiling = new Ceiling(World.GRASSLANDS.getTerrain());
         player = new Player(textures.player);
-        lock = new Lock();
     }
 
     public void setTexturePack(TexturePack texturePack) {
@@ -48,20 +46,21 @@ public abstract class Scene extends ArrayList<Entity> {
     }
 
     public void update(Timer timer) {
-        lock.lock();
-        Iterator<Entity> iterator = super.iterator();
-        while (iterator.hasNext()) {
-            Entity entity = iterator.next();
-            Vector movement = entity.getMovement();
-            Vector finalMovement = new Vector(movement).mul(timer.getFrameTime());
-            entity.move(finalMovement);
-            if (entity.isDestroyed() && entity.getDestroyEffect() != null)
-                entity.getDestroyEffect().createEffect(particleSystem, new Vector(entity.getPosition()), new Vector(entity.getWidth(), entity.getHeight())).start();
-            if (entity.equals(player))
-                moveEnviroment(finalMovement.x);
-            else if (entity.getRightEdge() - cameraX < -3f || entity.isDestroyed()) {
-                iterator.remove();
-                removeEntityFromAllLists(entity);
+        synchronized (this) {
+            Iterator<Entity> iterator = super.iterator();
+            while (iterator.hasNext()) {
+                Entity entity = iterator.next();
+                Vector movement = entity.getMovement();
+                Vector finalMovement = new Vector(movement).mul(timer.getFrameTime());
+                entity.move(finalMovement);
+                if (entity.isDestroyed() && entity.getDestroyEffect() != null)
+                    entity.getDestroyEffect().createEffect(particleSystem, new Vector(entity.getPosition()), new Vector(entity.getWidth(), entity.getHeight())).start();
+                if (entity.equals(player))
+                    moveEnviroment(finalMovement.x);
+                else if (entity.getRightEdge() - cameraX < -3f || entity.isDestroyed()) {
+                    iterator.remove();
+                    removeEntityFromAllLists(entity);
+                }
             }
         }
 
@@ -71,11 +70,10 @@ public abstract class Scene extends ArrayList<Entity> {
                 super.add(playerArrow);
             }
         } else super.remove(playerArrow);
-        lock.unlock();
     }
 
     @Override
-    public boolean remove(Object object) {
+    public synchronized boolean remove(Object object) {
         removeEntityFromAllLists((Entity) object);
         return super.remove(object);
     }
@@ -103,15 +101,15 @@ public abstract class Scene extends ArrayList<Entity> {
         this.screenSize = screenSize;
     }
 
-    public Background getBackground() {
+    public synchronized Background getBackground() {
         return background;
     }
 
-    public Terrain getTerrain() {
+    public synchronized Terrain getTerrain() {
         return terrain;
     }
 
-    public Ceiling getCeiling() {
+    public synchronized Ceiling getCeiling() {
         return ceiling;
     }
 
diff --git a/app/src/main/java/com/example/julian/endlessroll/rendering/renderer/GameRenderer.java b/app/src/main/java/com/example/julian/endlessroll/rendering/renderer/GameRenderer.java
index f1e5058..528fcb9 100644
--- a/app/src/main/java/com/example/julian/endlessroll/rendering/renderer/GameRenderer.java
+++ b/app/src/main/java/com/example/julian/endlessroll/rendering/renderer/GameRenderer.java
@@ -104,11 +104,9 @@ public class GameRenderer implements GLSurfaceView.Renderer {
             GLES20.glClearColor(1, 1, 1, 1.0f);
             GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
 
-            scene.lock.lock();
             renderEntities(gl, scene);
             renderTileList(gl, scene.getTerrain(), scene);
             renderTileList(gl, scene.getCeiling(), scene);
-            scene.lock.unlock();
             renderFbo(gl);
         }
     }
@@ -116,10 +114,14 @@ public class GameRenderer implements GLSurfaceView.Renderer {
     private void renderEntities(GL10 gl, Scene scene) {
         entityShader.start();
         entityShader.loadMVPMatrix(matrixCreator, scene.cameraX);
-        for (Entity backgroundPart : scene.getBackground())
-            renderEntity(gl, backgroundPart);
-        for (Entity entity : scene)
-            renderEntity(gl, entity);
+        synchronized (scene.getBackground()) {
+            for (Entity backgroundPart : scene.getBackground())
+                renderEntity(gl, backgroundPart);
+        }
+        synchronized (scene) {
+            for (Entity entity : scene)
+                renderEntity(gl, entity);
+        }
         entityShader.stop();
     }
 
@@ -135,11 +137,13 @@ public class GameRenderer implements GLSurfaceView.Renderer {
     private void renderTileList(GL10 gl, TileList tileList, Scene scene) {
         terrainShader.start();
         terrainShader.loadMVPMatrix(matrixCreator, scene.cameraX);
-        for (Tile tile : tileList) {
-            gl.glActiveTexture(GL10.GL_TEXTURE0);
-            gl.glBindTexture(GL10.GL_TEXTURE_2D, tile.getTexture().getId());
-            terrainShader.loadTransformationMatrix(matrixCreator, tile);
-            quad.draw();
+        synchronized (tileList) {
+            for (Tile tile : tileList) {
+                gl.glActiveTexture(GL10.GL_TEXTURE0);
+                gl.glBindTexture(GL10.GL_TEXTURE_2D, tile.getTexture().getId());
+                terrainShader.loadTransformationMatrix(matrixCreator, tile);
+                quad.draw();
+            }
         }
         terrainShader.stop();
     }
diff --git a/particlelab/particlelab.iml b/particlelab/particlelab.iml
index cc6a111..e2a5c28 100644
--- a/particlelab/particlelab.iml
+++ b/particlelab/particlelab.iml
@@ -66,14 +66,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/main/jni" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/shaders" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/jni" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
@@ -82,6 +74,14 @@
       <sourceFolder url="file://$MODULE_DIR$/src/test/jni" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/jni" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/assets" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/blame" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/classes" />