In Alien SOS you are an alien whose spaceship was hit by an asteroid and you've been thrown into a strange blue planet. Your job in each level is to find the portal so you can move on to the next level. Move with arrows or W,A,S,D. Use the mouse to shoot. You can only shoot blocks of grass to make them disappear, not the creature on your way. You have to outsmart the creatures by getting them to fall or get trapped so you can move around and collect weapon upgrades and find your way to the final level. There are forty levels in all and a level editor in Alien SOS!