Added extras.Button. Added @Property annotations instead of the clunky Behaviour.addProperties()
Refactored how aliens and ship yell, using a new helper class Talk.
Fixed bug with scene designer caused by removing y xais points down from the layer's constructor.
Added extra levels and images. Refactored the animations.
Halfway through adding multiple layers to the scene designer
Scenes can be designed using multiple layers. Scene loading is backwards compatable (but not forwards compatable).
Show/Hide layers in the scene designer
Copyright message to the top of source code