Columns © 1990 Sega Enterprises, Limited.

Sega's answer to the legendary "Tetris", the rules of Columns are simple : a column of 3 square pieces - stacked one on top of the other - drops from the top of the screen into the play area. As with Tetris, the column puzzle pieces can be moved left and right as they fall, but unlike Tetris, they cannot be rotated. Instead, pressing a button will cause the order of the colored blocks in a column to shift by one position.

The object of the game is to place columns at the bottom of the pit in such a way that lines of 3 or more like-colored blocks are created (either horizontally, vertically or diagonally). When this happens, these blocks disappear, and any blocks resting upon them immediately fall onto the recently vacated space. This will often cause additional lines to be arranged, producing a 'cascade' effect. The key to a long game (and, ultimately, a high score) is to set up these cascades wherever possible.

While not achieving the same legendary status as the mighty "Tetris" (something that no puzzle game can realistically hope to achieve), the 'Columns' series has managed to garner a dedicated following of its own and is a respected example of the genre.