The Idolm@ster is an enhanced version of the arcade game of the same name. Most elements from the arcade version remain unchanged, with the exception of new machanics inspired by the arcade mode. Save data is stored on the Xbox 360's internal hard drive or memory unit, and controls have been reworked for a more immersive experience. In-game models were also remade from scratch. There are no time limits to choosing songs or outfits.
The game features a new idol named Miki Hoshii, who is the main heroine and has a special storyline. Six new songs are included in the game, as well as downloadable content such as additional costumes and Idol Dramas.