Up arrow to thrust, right and left to turn, space to open the parachutes, S to stabilize, R to relaunch. The trick to getting to orbit is going above the atmosphere and going fast enough sideways. Can you make it into orbit and land back down? At the launch site? With fuel remaining in your tank? (It's possible.) Can you do a loop-de-loop?
This project is no longer being developed. I am in the process of combining it with my other project, Spaceflight Simulator. A proof-of-concept for rocket launch physics, not an actual game (although I guess it could be). I may make a game later (with a round planet, stage separation, and everything.)