Beatmania II DX 9th Style saw a revision to the game's hardware, replacing the Bemani Twinkle hardware with Bemani PC-based hardware which runs on a version of Windows XP. 9th Style was also the first in the series to utilise the e-AMUSEMENT card reader, which allows users to save scores and records.
Beatmania II DX 9th Style also featured a Beginner's mode which restricted the songlist to only very easy songs, and added 20 new songs into the mix.
Different software versions of the game are referred to as 'styles', with the different IIDX styles varying mainly in their songlists and graphical interfaces.
The controls across all of the different styles remain the same, with the Beatmania IIDX cabinet controls consisting of two turntables, and two keyboards each with seven keys. This is a main difference between the original Beatmania and the Beatmania II series, with the Beatmania keyboard only consisting of 5 buttons per player. Other notable features of the Beatmania IIDX cabinet are the widescreen 16:9 display; and the powerful speakers and bass platform that vibrates beneath the player's feet.
The gameplay involves the player selecting a song, with the player then having to match the notes by pressing the keys and scratching the turntable in time with the music.