Shift 3 is the latest iteration of the Shift game on Kongregate. You run around a maze with the right and left arrows, jump using the space bar, and shift to turn things upside down and make spaces into surfaces and surfaces into space.
If it sounds confusing, that's because it's hard to explain but easy to play. Incredibly addictive, and the "surprises" scared the wits out of me.
(From your mom)