Nice job! I was a little confused by the health being the main ship, rather than my own, but once I figured that out the game was a lot more fun. cool use of the theme. It was a little difficult to manage both the top and bottom areas of the ship, I almost feel like it would work even better as a 2D game rather than a 3d one, because that tether mechanic is awesome, but a little frustrating when trying to move from the bottom of the ship to the top quickly. Also as has already been said below, if there was a way to make it more initially obvious that the asteroids are good to smash into that would make that first attempt a little more addictive. I actually missed the instruction the first time through, so that might just be on me though.
Good job and best of luck!