Beatmania IIDX 17: Sirius is the 17th installment in Konami's Beatmania IIDX series of music video games. The main motif of Sirius's UI is astronomy, as the game is named after Sirius, known to be the brightest star in the night sky. Public location tests began on May 27, 2009,^[1] and the game itself was released on October 21, 2009.^[2]

The existence of a 17th version in the beatmania IIDX series was confirmed by Konami on May 25, 2009, alongside the announcement of the first public location tests at the Cat's Eye arcade in Japan,^[1] which had already been promoting the location tests set to begin on the 27th of May for several days before the official announcement.^[3]

The location tests revealed new features contained in the game, such as "charge notes", and contained a sampling of songs slated to be included in the final release.^[4] Additional tests were held in late June to early July in Nagoya and at an arcade at the Norbesa in Sapporo.^[5]

Beatmania IIDX tasks the player with performing songs through a controller consisting of seven key buttons and a scratchable turntable.^[6] Hitting the notes with strong timing increases the score and groove gauge bar, allowing the player to finish the stage. Failing to do so depletes the gauge until it is empty, abruptly ending the song.^[7]

Sirius adds two additional note types to the game, "charge notes", or Hold-me Notes which must be held for their duration, and the "back spin scratch", a type of scratching which must be spun on one direction continuously and spun again to the opposite side at the end of the note. Selected songs contained these features in the location test build.^[3]

A new "party mode" consists of a story mode where players earn "fans" based on their performances.^[2]

Another new mode, "League Mode" is a course where each song is selected based on the grade that they chose, from D grade to S grade. Songs chosen and the score that earns will convert into League points in the end. The selected songs number is ranged from 4 to 12. The score from this mode is also available to upgrade their own standards.^[2]

There are 66 new songs and 512 songs carried over from previous releases for a total of 578 songs in this game. The entire song list contains songs by Konami original artists and others.^[2]