Am I the only one who doesn't understand the symbolism? I get that the yellow ball is culture, is the outer circle the people? What about the inner circle?
Not bad for a first game. Tips:
1) Have a firing variable, set it to 0 at first, and 1 when you press space after firing the missile, then not fire if it's set to one. That way, you can have a missile fire when space is *pressed*. 2)More enemies should be able to be on screen, and the arena either needs to be smaller, the character faster, or the sides looping. This way, you can reach otherwise impossible enemies.