Cruel space

Grab your guns, run around the small planets, blast everything in sight, take off, buy upgrades, ad infinitum! Definitely good looking and plays nice too. One downside for casual players is that you have only 1 life (3 energy bars) to play the whole game so if you lose it's back at the beginning. To which I must reply: just play better :D

Play online or grab a downloadable version or source