Roguelike Asteroids is a good idea that I would like to see developed further.
Three things that I would suggest changing after the jam:
1) make the screen bigger - it felt a bit too cramped, which made me never want to pick a speed upgrade because the risk of crashing in asteroids by accident seemed too high;
2) change the shoot input from mouse click to space; and change the thruster from space to W (also, maybe duplicate these controls on the arrow keys) - it feels a bit odd to use a mouse just for a button click; and
3) make some smaller and faster asteroids (this goes well in combination with making the screen bigger) - another reason I avoided speed upgrades was because I didn't feel like I needed them because the asteroids were all big and slow.