Osu! is a free-to-play rhythm game in which players click circles, sliders and spinners in time with music, so rapid mouse and keyboard tapping is central to how it is played and watched. Short recordings of that frantic clicking spread through gameplay videos, streams and short-form edits, where the sound alone could signal a difficult map or an intense play session. It remains popular because it is instantly recognisable to rhythm-game fans and works as shorthand for speed, skill and concentration, even for viewers who have never played the game themselves.