Smash things! Smash lots of things in lots of ways and have heaps of fun doing it! It gets pretty hard, too, what with aliens not really liking it when you smash their stuff.
Arrows or WASD - Move. Space/Shift - BOOST. TAB - View Upgrades and Map. Z/R - Implode. X/F - Explode. C/T - Slow time. M/~ - Mute.