Keep at it!
First off, it was a well made game that ran fluidly, there were a few problems I found however. My first suggestion would be to speed up the pace, if it's a UFO racing game that's space based I personally believe that it should be a much quicker game, the racing went quite slow. Also the turbo, as everyone else is saying, needs to replenish itself. The graphics aren't too bad and the simplicity allows for a smoother perfomance. It was a nice try and a decent game, there are just a few things I believe need to be worked. The menu system was great by the way, very fluid and well executed. Keep workin' at it!
~Dylan