User Summary Grinder is a stylish but gruelingly difficult science-fiction platformer for the iOS. You control two characters, one on each side of the screen. You must guide the character on the left UP, past deadly obstacles and enemies. You must guide the character on the right ACROSS, over bottomless pits and other hazards. And you must do both things simultaneously. Grinder features stylish black-and-white art and a custom soundtrack. But its most distinguishing feature is the near impossibility of surviving more than a few minutes.