I've made the bullets recharge now. I've also made the enemies go up and down! You can turn the sound on and off with M and N (which sounds like candy) now, but there's no icon yet.
Thanks, man! I made it so you only have three bullets because it seemed too easy if you could just go all Rambo on the aliens. But I didn't know about the high score thing, thanks for telling me. It's fixed now.