Ragnarok Online is a long-running massively multiplayer online role-playing game first released in South Korea in 2002, and its level-up sound became one of its most recognisable audio cues. In the game it signals that a character has gained enough experience to grow stronger, unlocking new skills and stats. As gameplay clips, streams and reaction videos spread online, the short jingle moved beyond its original players and became a shorthand for progress in general. Creators still use it today because it instantly communicates achievement without needing any explanation.