Classic game, love that you made the ship a shuttle :-) My two cents, I think the controls would be better as rotate +, rotate -, and burn rocket instead of the UDLR you used, especially if you're going to emphasize the space physics aspect. I think it would also make it a little spacey-er if you reduced the acceleration of the rocket a little, but increase the top speed it will achieve by a lot. Also, why does the fuel go away so fast when not firing rockets?