Tetris (Russian: Те́трис, pronounced [ˈtɛtrʲɪs]) is a tile-matching puzzle video game, originally designed and programmed by Russian game designer Alexey Pajitnov. It was released on June 6, 1984, while he was working for the Dorodnicyn Computing Centre of the Academy of Science of the USSR in Moscow. He derived its name from the Greek numerical prefix tetra- (all of the game's pieces contain four segments) and tennis, Pajitnov's favorite sport.

Tetris was the first entertainment software to be exported from the USSR to the US, where it was published by Spectrum HoloByte for Commodore 64 and IBM PC. The Tetris game is a popular use of tetrominoes, the four-element special case of polyominoes. Polyominoes have been used in popular puzzles since at least 1907, and the name was given by the mathematician Solomon W. Golomb in 1953. However, even the enumeration of pentominoes is dated to antiquity.

The game (or one of its many variants) is available for nearly every video game console and computer operating system, as well as on devices such as graphing calculators, mobile phones, portable media players, PDAs, Network music players and even as an Easter egg on non-media products like oscilloscopes. It has even inspired Tetris serving dishes and been played on the sides of various buildings.

While versions of Tetris were sold for a range of 1980s home computer platforms as well as arcades, it was the hugely successful handheld version for the Game Boy launched in 1989 that established the game as one of the most popular ever. Electronic Gaming Monthly's 100th issue had Tetris in first place as "Greatest Game of All Time". In 2007, Tetris came in second place in IGN's "100 Greatest Video Games of All Time". In January 2010, it was announced that the Tetris franchise had sold more than 170 million copies, approximately 70 million physical copies and over 100 million copies for cell phones, making it the best selling paid-downloaded game of all time. On 14 March 2014, The Tetris Company announced a deal to bring Tetris to two of the latest hardware platforms, the Xbox One and PlayStation 4, in partnership with Ubisoft (publishing) and SoMa Play (development), to coincide with the franchise's 30th anniversary.

Flappy (フラッピー, Furappī) is a puzzle game by dB-Soft in the same vein as the Eggerland series and Sokoban that is obscure outside Japan. It features Flappy, a somewhat mole-like character who must complete each level by pushing a blue stone from its starting place to the blue tile destination.

Flappy first appeared on the Sharp X1 home computer in 1983. This debut was soon followed by conversions to a number of popular Japanese computers in the early 1980s, including the NEC's line of PCs and the Fujitsu FM series. As a puzzle game, it was well suited to these early systems since it did not require a tremendous amount of graphical sophistication. Ports for the MSX computer line and the Family Computer were released in 1985. DB-Soft produced a sequel with more difficult puzzles called King Flappy for the benefit of anyone who managed to clear the original 200 levels. A Nintendo Game Boy port was released exclusively in Japan in 1990 and was published by Victor Musical Industries. Over time, Flappy has continued to see many graphically improved upgrades, such as on the Windows platform and on several mobile phone devices. It was released on Japan's Virtual Console in 2007.

Two officially-unreleased variants of Flappy, Floppy and Beyond Floppy, were programmed by Greg Hale and Ted Cohn for the Apple II platform. Floppy featured special names for each of the game's levels. Included with both Apple II games was an editor which allowed the user to create their own custom levels.