Blast as many enemies as you can before you're defeated.
Mouse to move and shoot. Right Click to Pause (for now). Weapons go to your right or left hardpoint depending on where you grab it. EXP applies to all weapons; you lose nothing by switching a weapon. There are 9 weapons: Vulcan, Railgun, Spread Shot, Mega Missile, Laser Lance, Plasma Thrower, Blade Missile, Bits and X-Shot. The enemies get more exciting as you go.