
While Portal 2's single player offered a hardy challenge, the real mind benders are found in the co-op campaign. The possibilities are much bigger with four portals, and it can be frustrating when two brains can't crack the puzzle. While we don't recommend using the guide for the whole thing, working your noggin is kind of the whole point, getting frustrated at a particular puzzle happens to the best of us. Thankfully we've noodled out all the solutions for you so you can check out our video walkthroughs if you encounter a particularly difficult challenge.

Portal 2's unexpected solutions are what make it fun, but sometimes things just don't click. If, after applying caffeine and barraging your screen with bewildered expressions and long sighs, you remain stuck, this guide will send you in the right direction with textual descriptions and videos of every challenge in the game. Just be warned that, because Portal 2's gameplay and story are heavily intertwined, this guide CONTAINS SPOILERS. If you don't want any dialog spoiled, hit mute before watching any of the videos...