I don't usually like video games. In fact, the only games I've played for longer than an hour are Minesweeper, The Sims, and Portal. In Portal, you must solve puzzles using your "handheld portal device", which you really need to see to understand. Throughout, you are prodded onward by an increasingly malicious AI named GLaDOS. Your only friend (for a brief time) is the Weighted Companion Cube, which is, as the name implies, an inanimate cube.