Ninety percent standing around, ten percent absolute chaos, and somehow that ratio just works.
Fun fact: "Every regulation ball has exactly 108 hand-stitched red cotton stitches holding its cowhide cover together."
GLaDOS is the funniest character in games and she spends the whole time calling you fat and stupid.
Fun fact: Began development as a prequel called "F-STOP" that had no portals at all.