it comes with a pretty interesting story:
Tetris is a 1988 Sega System 16 game developed and published by Sega. It was licensed from Atari Games (credited as Tengen) and Mirrorsoft, who held the rights to produce Tetris arcade games at the time. A less powerful version was also released for Sega System E hardware. Both versions are unrelated to Atari's arcade version, released in the same year under the same name.
Sega attempted to port the game to the Sega Mega Drive, however sales were blocked by Nintendo who owned the home console rights to the franchise (they had taken Atari's home console division, Tengen to court over a similar incident on the NES). As such, only about 10 cartridges were produced, all of which were only released in Japan. This version is now a rare collector's item, being sold in auctions for up to US$16000. Because Nintendo had no authority over the arcade versions, the Sega Mega Drive port was brought to Mega-Tech hardware in 1989