Left / Right: change direction. Up: thrust forward. Down: move backwards. There are special techniques once you have reached a certain level: - Hyperspace: level 2. - Shield: level 3.
This is the 4-level Scratch Version of the classic game "Asteroids". "Star Clash 2": http://scratch.mit.edu/projects/585256/ Music: "T-Maxx" by Peter Wagner. http://www.prwmusic.com/songs-songinfo.html