The underground theme comes from Super Mario Bros, the Nintendo platform game released in 1985, where it plays in the game's subterranean stages filled with bricks, pipes and coins. Koji Kondo composed the game's music, and the short, looping cave theme became closely linked with exploring hidden areas. Short beat edits like this one circulate online because they are easy to loop, instantly recognisable to gamers, and fit retro edits, speedruns and meme videos without needing a long musical intro.