Portal 2 sits comfortably atop the summit of fantastic linear games. Where Portal 1's story and general gameplay trajectory is a gradual build-up to an explosive ending, Portal 2 feels a lot closer to a genuine rollercoaster, where mechanics are introduced and expanded upon to just the right amount until an exciting story beat drops you 100 feet as the momentum pushes you through over and over until the very end, leaving you saying "Damn, that was awesome".