Marathon Mode

Marathon Mode is a 20-level game mode in Tetris DS. It features music from a game in the Nintendo Entertainment System-era, a background with characters from the game and closeup sprite from the game on the bottom screen that spins rapidly when points are accumulated. The first 10 levels are based on Super Mario Bros. and Super Mario Bros. 3, although level 12 is centered around Metroid. It plays a remix of the Brinstar theme, like in Catch Mode, albeit slightly faster.

In level 12, on the bottom screen, Mother Brain is seen in the background, and the sprite of Samus from the file select in Metroid{{'}]s Famicom Disk System version is the closeup sprite shown beside the playing field. On the top screen, Samus can be seen jumping around in the starting point of Brinstar, although the Morph Ball is missing and the background is colored red, a contrast to the blue rock scenery of Brinstar. Two Zoomers are present on the midair structures above the starting point, as they are in Metroid.