Tommy's Nyet is a DOS Tetris clone for one to six players. The player uses the numeric keypad to position falling blocks in a pit. Blocks can be moved right or left and they can be rotated too. When the player completes a row of bricks across the pit with no gaps, that row disappears and all remaining bricks in the pit drop down. When blocks are moved left or right they are moved in half-brick increments which, if the block comes to rest in this position, leads to rows of blocks that can never be completed.

Each row that is completed scores one hundred points. Each falling block scores points for every level it falls before coming to rest. The number of points scored is either equal to the level of difficulty, if 'peek mode' is enabled, or three times the level of difficulty if 'peek mode' is not enabled. 'Peek mode' is a switchable feature that allows the player to see the shape of the next block. The game has nine levels of difficulty and maintains the top ten scores for each level.