Snake 3D adds depth to the classic two-dimensional game; hold shift and you'll move in and out rather than up, down, left or right. It takes so much getting used to--and is so difficult before you even get to the point where the snake's length becomes a hazard to itself--that I suspect that the entire premise is beyond the threshold of human patience, if not comprehension. See 1989's Welltris, from Tetris creator Alexey Pajitnov and Andrei Sgenov, a game design that only makes sense as the result of failing to make a more obvious implementation of 3D Tetris playable. Emboldened by superior 3D graphics in the late 1990s, Nintendo eventually implemented 3D Tetris itself but it wasn't much more fun than Block Out. Nowadays, some form of 3D Tetris sometimes shows up as a "go fuck yourself" mode on normal Tetris games.
