Alpha 0.2 - Enemies Update

In this update, enemies (threat) have been added.

Change logs:

Added a gun - the penguin carries it with him. The gun Shoots at the access space.

Added 4th level.

Added Enemy - Crabot - attacks close.

Added enemy - CraGun. Shoots from his cannons.

Opponents have been added to each level.

Added sounds.

Added music.