3D Tetris

3D Tetris is a puzzle game that uses a three-dimensional playing field as opposed to the traditional two dimensions used in most other versions of Tetris . The play field, called a well, contains 5 vertical layers that players fill with falling three-dimensional blocks. These blocks can be rotated horizontally and vertically, as well as positioned in four different directions. Each block displays a shadow underneath it which indicates where it will land.

The game's camera continually adjusts itself, but players can manually readjust it. The HUD displays a radar which provides information about each of the well's five layers, as well as the next block to fall, which is represented by a character. The game contains multiple different modes: 3-D Tetris, Center-Fill, and Puzzle, each having variations in how they play. Players can modify the difficulty in these modes as well as the rate by which the blocks fall.

In the 3-D Tetris mode, a layer disappears when it is filled with blocks, scoring players points which are displayed in the HUD. If blocks stack over the top of the well, the number of layers will go down by one. The game is over when the final layer is lost. One game mode is based on accumulating points, while the other mode requires players to complete multiple levels by clearing all five layers in each.

In the Center-Fill mode, players place blocks in symmetrical patterns around center blocks placed in each well's layers. If a block is placed in a layer's center block, it disappears, and any other blocks in the layer will also disappear, if they have been successfully placed in a symmetrical pattern. Points are gained based on the number of blocks in, the complexity of, and the height of the symmetrical layer. A symmetrical pattern is indicated by a symbol shown in the HUD's radar, as well as the player's score.

Like the 3-D Tetris mode, layers will be lost if the blocks go over the top of the well, and the game ends when all layers are lost. One variant requires players to complete as many layers as possible, while the other is the same except with obstacles added. The variant Clear It! requires players to clear ten symmetrical layers on each stage to progress to the next stage.

In the Puzzle mode, a shape is displayed in the well at the beginning of each stage. Players are tasked with getting to the highest stage possible by placing blocks in the displayed shape to progress to the next stage. At the end of each stage, a stage-ending animation is displayed. If an incorrect shape is placed, the game ends.

3D Tetris includes an option to save high scores and names entered from the 3-D Tetris and Center-Fill modes, along with progress in the Puzzle mode, to a battery backup.