Friday Game: Space Rubbish
.Like Asteroids, but with better physics, and an upgrade system. Lots of fun, quite addictive, I highly recommend it: Space Rubbish. There’s a playable demo as well, which is also fun—one of my few quibbles with having bought the game is that the “arcade mode” of the demo isn’t available with the purchased game.
It’s cross-platform, and definitely worth the minimal amount the author is charging for it.