Pop'n Music (ポップンミュージック), most commonly shortened to Pop'n, PM or PNM, is a music video game in Konami's Bemani series. The game is notable for its bright colors, upbeat songs, and cute character graphics. Although Pop'n Music was originally intended to be played by couples on dates, it has greatly escalated in difficulty since early iterations, and has since then attracted many players of Beatmania and other Bemani games.
Introduced in Pop'n Music 9 is Osusume (オススメ, Lit. "Recommendation") Mode, where the player is asked a series of questions, and the game provides an Expert course based on the player's answers.
Source: Wikipedia, "Pop'n music", available under the CC-BY-SA License.
The Arcade version contains all the music from Pop'n Music 1-8. Pop'n Music 9 was the third home console version published on the PlayStation 2.