Good conceptually, but this game is at war with itself. I want to get more bullets in the air, but they move quite fast and are hard to dodge, so I'm making my own life much harder.
I would prefer if either the bullets moved slower or didn't hurt the player. There may be balance changes required for that to work.
I initially thought aiming with the arrow keys would be unplayable, but it doesn't really matter if you hit. This game tests your dodging skills much more than your aiming skills. Still, I think mouse aiming would be better simply to get more variety in the bullet paths on the screen.
Good entry - for all my criticism, I did have fun playing it!