Ben Weber, a Ph.D candidate in computer science at UC Santa Cruz, has programmed a devious game using the familiar sprites and backgrounds of Super Mario World. Weber’s Infinite Adaptive Mario starts off with a level of moderate difficulty. Once you beat that, the next level gets harder, and the levels continue to get harder until you die three times in a row without completing a level, at which point it gets easier. And yes — “harder” really means “harder” here: It doesn’t take many levels before you encounter an enemy-infested mess comprised of the trickiest jumps.