Little Green Planet (Ludum Dare 38)

A small arcade game. You are a little fellow that lives on a Little Green Planet that is under attack by aliens. You have to shoot the aliens down before they reach the surface of your planet. When the aliens reach the planet they will start eating away at its crust. When the planet takes too much damage, the outer layer will collapse and your planet will shrink, revealing the next layer. Try to survive as long as possible!