3D Block is a puzzle video game for the Nintendo Entertainment System, inspired by the 3D mechanics of Tetris. It features a fixed well size of 5x5x10 cubes and includes block designs from the arcade version of Blockout. Unique controls allow the Select button to pause the game, while the Start button accelerates block descent, distinguishing it from conventional gameplay mechanics.
This is an adaptation of Blockout, which in itself is a 3D version of Tetris. This is emphasized with the cartridge itself, having the artwork ripped from the original game. In this version the well is 5x5x10 cubes large and the size never changes, unlike the official versions. The controls are somewhat unorthodox, as unlike most other games, the Select button pauses the game while Start speeds up the block so that it moves to the bottom of the well faster. The block designs themselves are the same as in the arcade version of Blockout.