In IIDX games, players recreate the musical score of songs available to them through the use of a DJ simulating controller.[ The player must coordinate their hands in order to hit the correct keyboard buttons, spin the turntable, or a combination of both in correspondence to color coded notes that approach the judgement bar displayed on screen.
Source: Wikipedia, "Beatmania IIDX", available under the CC-BY-SA License.
beatmania IIDX 2nd Style saw the introduction of Battle Mode, Double (14-key) mode, and Hi-Speed settings.
Source: Wikipedia, "Beatmania IIDX 2nd Style", available under the CC-BY-SA License.