Explore the missions of a campaign mode or survive a marathon with a special spaceship. Travel around the frozen moons, shooting alien ships. Move the Mouse to aim and click to shoot, moving around with the WASD and Arrow keys, never giving up and dodging the bullets that drive faster than the aliens are summoned. Space-bar is useful when the bombs are collected. Until then, varying the guns collected by pressing the numbers in the keyboard's Numberpad should be enough. Activate a powerful and temporary shield with R key and keep surviving the increasingly and incredibly hard waves, one after the other.