The Game Boy Color update of Tetris released as a 1998 launch title was Tetris DX.
Nintendo developed Tetris DX as an enhanced version of its classic Game Boy Tetris. It added color graphics, battery-backed saved data, player profiles, new music, and additional modes while preserving the familiar falling-block puzzle.
The game launched in Japan on October 21, 1998, shortly after the Game Boy Color debuted, and followed in North America on November 18. Its extra modes included Ultra, which used a time limit, and 40 Lines, which challenged players to clear a set number of lines quickly.
A common mix-up is confusing Tetris DX with Tetris Plus, Tetris Worlds, or Tetris DS. Those are separate games or releases: Tetris DX is specifically the Nintendo Game Boy Color revision and is recognized as part of the system’s launch lineup.