An engine or sets of classes and function necessary for an isometric tower defence mobile game (iPhone, iPad, Android). This engine must have all functions as explained in the spec. The engine must have the ability to render images, add button, have a game loop and be able to connect to apple appstore and google play to purchase items. The game map must be xml/json or Tilemap based. all object must also be xml/json based. The game must run on landscape mode. The development must be in Cocos2djs.