It's Tetris as we all remember it. Drop different shaped blocks into the container, and fit them together to form a horizontal line, and the line disappears. Your job is to keep going as long as possible by clearing the container of blocks.
This will be the first time on a Game Boy System that 4 players can play multiplayer Tetris, which is much the same as the original Tetris, only that when you clear a line of blocks, the line(s) appear in another players screen.
On the Game Boy Advance version of Tetris Worlds, when you're in the "SELECT GAME" screen for Marathon mode play, press left-shoulder and select at the same time to get a new game variant: POPULAR TETRIS. We wanted to include a more "classic" version of Tetris in the game, since it was what some people were asking for. It uses the same scoring used by the older Game Boy Tetris, for those players who like to go for high scores.