beatmania IIDX 3rd Style removed the 4-keys mode from the game and replaced it with a Light7 difficulty. This gave most songs a completely separate, easier notechart. In addition, 3rd Style introduced Free Mode and Extra Stage.
beatmania IIDX 3rd Style: The first of the PlayStation 2 games in the IIDX series. This combines select songs from styles 1, 2, and 3. Some songs remain arcade-exclusive.