I really liked the game, the idea is cool and can even became addicting. One thing i noticed though is that engine thrust might be very underpowerd: going fast is not really that important and stronger thrust can even be negative because it pushes you away from the asteroids you are mining quicker. Going fast is also dangerous because it's easier going against asteroids. I would also probably have prefered if there was only a button to use engines, on the left mouse button.
Btw really cool game ;)
Would you mind trying my entry too? Thanks!