Columns
Columns is a non-tetromino game franchise, developed by Sega as a response to the popularity of Tetris in regions where companies other than Sega had an exclusive Tetris license from Elorg. Many Sega Game Gear handheld systems were bundled with Columns.
Columns uses only the I trimino, where each block is colored with one of a selection of four to six colors. The player can move the piece sideways into a playfield whose width may be 6 or 7 blocks and whose height is variable (12 to 18 blocks depending on version). The pieces cannot be rotated, but the colors within the piece can be rotated. After the piece locks, three or more of the same blocks aligned horizontally, vertically, or diagonally disappear, and the blocks on top fall into place, possibly causing a cascade.