New Super Mario Bros. 2 was released by Nintendo for the Nintendo 3DS in 2012, continuing the side-scrolling Mario series with a heavy focus on collecting coins. Its underground theme plays in the game's subterranean levels, where Mario travels through caves and pipes away from the bright overworld. The track later spread through gameplay uploads, Mario compilations and soundboard sites, where players recognised it instantly from its enclosed, echoing feel. It remains popular because it signals exploration and hidden areas in a single familiar tune.