This is a list of variants of the game Tetris. It includes officially licensed Tetris sequels, as well as unofficial clones. In 2017 Guinness World Records reported Tetris to be the game with most official versions released at 220, over 65 different platforms.^[1]

• Ultimate Tetris is a Tetris game that has more than 20 block types, a few new game modes, and a "Hardcore" mode where the game is played on a 125x125 grid.

• PicTiles is a variant of Tetris in which the tetrominoes are used to fill in pictures. The game is available as shareware for OS X (PPC and Intel) and was originally released in 2004 by Charcoal Design (website).

• California Dreams released a Tetris variant called Blockout (website) in 1989. It is played in three dimensions from a top-down perspective. The basic mode uses standard tetrominos, which can be manipulated with three different degrees of rotation, in two directions (requiring six separate keys for rotating, in addition to the four movement keys and a key to drop a tetromino). Further modes in the game introduce extra dominos composed of blocks set above and below each other, and may have more or less than four blocks. www.blockout.de international championships

• Eqtris () is a clone with numerous gameplay variations, including competitive and co-operative two-player modes, editable game pieces, and a mission-based Challenge Mode.

• Gravytris (www.gravytris.de) is a freeware implementation of Tetris in OpenGL that implements the "chain-reaction" variant of gravity. Furthermore, it has a contemplative puzzle mode with complex tiles and no time pressure. Another game mode is color tetris where a strategic twist is introduced by adding colored subblocks to the tetris tiles effectively combining the games Columns and Tetris into one game. Other features: Online Highscorelist, 1-hour soundtrack, windows and Linux binaries, no installation required (single self-contained executable)

• Bastet, short for Bastard Tetris, is a Tetris clone created by Federico Poloni. Running on the Linux platform, Bastet increases the game's challenge by using a mathematical formula to choose the worst possible tetromino to give the player, rather than selecting one randomly.

• Vertris, is a simple cross-platform Tetris clone created by Andrés Rassol. It is covered under the GNU General Public License.

• TetriNET is a popular variant playable on Internet with up to 6 players. On clearing lines the player receives special blocks that can be used to damage the field of the opponent or help a teammate. This imitation uses general Tetris inferences, but the main differential is its 12 by 22 play field dimensions.

• Duotris is a Tetris clone produced by team Magnetics, which was released on Commodore 64. It featured classic 2D tetrominos and included a standard singleplayer mode, a two-player split-screen mode as well as a unique team mode in which both players filled up the same playing area.

• Tetripz is also a freeware game for the PC, written by Mute Fantasies. It has a number of levels that alter the appearance of the game board (by spinning, warping or otherwise changing the traditional board). It is, according to the game designers, "playing Tetris under influence of LSD, but without the LSD." The row width is 11 blocks wide.
• Tetanus On Drugs is a free software game for Windows and Linux, and it is also ported to Game Boy Advance ROM. The game was developed by Pin Eight, and, while not stated by its website, it is probably based on the earlier game Tetripz. Tetanus On Drugs plays on more traditional restrictions with a mode similar to The New Tetris.

• Tetris Worlds (NHN Corp, 2005) is a Korean interpretation of THQ's original Tetris Worlds. In NHN Corp's game, a player can rotate floored tetriminoes up to 15 times. The game includes modes of play similar to THQ's Tetris Worlds but also includes Tetris clear, where users compete in terms of time to clear lines containing "star" mino; survival, where users compete against each other like in other versus mode games; Sticky; Cascade; and Rush mode. Rush mode uses Cascade gravity and has 100 to 150 unfilled rows that a player needs to "dig down" using line clears and attack or defend items. The first player to clear the bottom row wins. The game also features Single Player puzzle mode and has multiplayer support for up to 6 players in Tetris/Sticky/Cascade and a maximum of 10 players in Rush mode. It is playable at http://tetris.hangame.com/.

• Emacs has a Tetris easter egg available by typing ESC-x then tetris (or pong)

• Phony Ring two:five is a variant of Tetris in which the playing field is a ring. It is a PC game released in 2006 by Volatile Assembly (website) with the music highly integrated with the game flow.

• Lockjaw is an open-source Tetris clone designed to accurately play like a range of popular Tetris games. It is largely customizable by the player.

• "Triz" is a Tetris clone made for Symbian OS. One important note is that it does not show you the next piece.

• Quadrapassel (Formerly Gnometris) is a part of Gnome Games, and is installed by default with the Ubuntu distribution of Linux.

• Scrablet is a variant where the basic game of Tetris is combined with Scrabble. The game feature an inbuilt dictionary of over 20,000 words. Scrablet won the Champion (Games Category) in National Software Competition held in Singapore in 1991.

• List of puzzle video games