I'm currently working on the battleship enemy. Battleships fly around the top of the screen, shooting down lasers from their three cannons. Right now they are invincible.
Next I have to make it so the battleship can parachute little infantry robots in. Than after that I can get started on the Robot Tank enemy.
Hopefully the theme of this level is starting to seem apparent. In this case, it feels like an invasion.
Just an off-topic note, if you ever want to be productive, don't start playing Civilization 4[smile]