I like the art, but the animation's a bit lacking... Maybe a few more frames in the jump? The penalty for not making the jumps seems a little heavy too at times. Maybe make it so that the floor is clearly going to kill you, rather than looking like you can jump onto it.
With the current version of flash and firefox this game doesn't display properly and later scripts make it crash. Use internet explorer if you want to play with ships that actually appear!
Trying to get the stars after finishing the game is problematic, as there is no option to play on after you complete the level (with or without collecting the stars). You have to either submit the score or reset points, both extremely annoying options. Great game, though.
Shields getting hit invalidate the insane no hit achievement. got hit by enemy #1492, lost shield. Didn't lose any health, but didn't get award.
Keyboard -> wall