Puzzle platform game that only real shortcoming is that it's to short :). In it the character you play is stuck in a laboratory and subjected to experiment by a AI named GlaDOS. You are forced to use a portal gun that creates space portals between flat surfaces to solve puzzles by GlaDOS while you are looking for a way to escape the laboratory. The sad part is that when you finally get a hang of the portal gun the game end's so it feels like playing only the tutorial part of a full game :(.