Please add Mouse for controls? I also suggest that there are a sign or symbol that would indicate that our controls would be reversed, so that players are not being hosed during the middle of playing. It's quite irritating.
For the design, you could consider furthering the design: adding a BG to the Game over screen, and including a variety of different obstacles other than those space rocks. There could be meteorites, satellites, and many other ideas that the player must dodge. The possibilities are endless.
Thank you for your feedback. I don't think I can add the mouse for controls, not that I can't for the basic control, but I really don't know how I will be able to switch them. I think it would be way more irritating since you'll move faster and will collide easily with an obstacle.
A warning is something that I'll totally be working on. Also yeah, I didn't even thought about including other obstacles. It's a great idea ! Thanks !