Use WASD to control the lander ship. The object is to land, CAREFULLY, on a landing pad. If you're moving too fast, you will crash. You must be facing up, or you will crash. If you run out of fuel, you're going to have a bad time. And you will crash. Later levels add a UFO that fires at you and an Alien monster who will try to wreck your ship. Avoid it or take advantage of the UFO's deadly lasers to take it out.
AKA "Lunar Lander" ... with stuff. "Alien" sprite remixed from "Collision Detection" project: http://scratch.mit.edu/projects/2747975/