looks like an interesteing consept but the flipping action needs a lot of smoothing out to make in more understandable. i''d consider adding the ability to walk from one wall to the other, flipping gravity as you go; strait up and down don't give you enough directions for an interesting puzzle game. Let me know when some changes have been mad and i'll give it a test run.
In some games you'd be duke nukem on the roof, in others the fat smelly guys who's still alive because he never left his bus, but here you can do both!! awsome game!
Not as bad as some people are saying, controls just need a little getting use to. Please play games past the first level before complaining about the control set up.
In response to the issue of friction: You could add a second mode (Hard or realistic, or something along those lines) in which you added harder controls, less energy, and maybe faster 'roids. Hope this helps you come up with some new ideas.
A few more suggestions: 1) Kill the friction, seems strange since we are in space. 2) location specific damage (not my idea but felt it should be reposted) such as damaged thrustors, missle launchers, ect. 3) Comet which will pull asteroids that hit it, and if hit my a missle will vent gas in that direction, thrusting the comet in that direction and spewing out energy. Keep up the good work GameDesign