Plants vs Zombies is a tower defence game first released by PopCap in 2009, in which players defend a garden from waves of zombies using different plants. Its light, catchy music helped make the game instantly recognisable, and piano versions and arrangements have long circulated among fans who recreate its themes outside the game. On short-form video and soundboard sites, this kind of calm piano clip is now reused as a nostalgic shorthand for the game itself, even by viewers who remember the gameplay more than any single track.