Tetra is a block-puzzle game similar to classic Tetris. The player arranges polyomino shapes on a dark blue grid-style board to create 10-block rows. Every time the player completes a line, they receive coins and points for their efforts. Their goal is to earn these rewards for as long as possible.
As with the original game, Tetra drops the shapes onto the board from above. The player can rotate the shapes to make lines faster. If they remove four lines at a time, they achieve "Tetra" status.
The game displays three shapes to the right of the board. It also assigns the same color to the same shapes and highlights the color of the next shape in line. As a result, the player can plan placement decisions ahead while they wait for a shape to drop into place. They can also force a shape to drop faster with their controls.
Tetra speeds up the drop rate automatically as time passes as well in an attempt to trick the player into making placement mistakes that bar the completions of one or more rows. The player must make precise placements or risk creating gaps in lines below the top row or stacking shapes until no more room exists on the board.
