You have one little problem. The tiny enemies are "invincible". you have their die method using the small enemy's die method. Therefore it keeps spawning tiny enemies. You need to overwrite the die method in the tiny enemy's code.

thanks for telling me about that. I didn't think about that till now. I will have that fixed soon.

tkiesel you should put a backwards method in there and make a turbo boost that burns for about a second then takes about another 30 seconds to recharge.