The original game features 10 songs the idols perform, which is increased to 16 in the Xbox 360 version, later released on several music albums.

The Idolmaster is a raising simulation game in which the player assumes the role of a producer working for the talent agency 765 Production (765 Pro) who is in charge of training 10 prospective pop idols on their way to stardom.

They include: Haruka Amami, Chihaya Kisaragi, Yukiho Hagiwara, Yayoi Takatsuki, Ritsuko Akizuki, Azusa Miura, Iori Minase, Makoto Kikuchi, and Ami and Mami Futami (who work as a pair).

The player can view the state of an idol's statistics at this time, which are divided into three categories: vocal, dance and visual image.

[3][4]The lessons are in the form of five minigames which serve to increase an idol's statistics in either vocal, dance or visual image.

Each costume and song have either a vocal, dance or visual attribute which will affect the idol's statistics and thus the results of the audition.

When taking an audition, the player guides the idol to appeal to three judges in vocal, dance and visual image by receiving points in each category.

If one judge is appealed to too many times, their interest level may drop to zero, at which point all the stars earned for that category will be revoked.

The player also has the option to use up to three good memories during each audition which serve to dramatically increase an idol's appeal points and the gauges for the judges.

[7] In the case of a multiple idol unit, the player can choose who sings which lyrics, though at least one singer is needed for each line.

[8] If the player chooses to take the day off, a conversation event will sometimes occur, but does not include any choices for responses as during the normal communication phase.

Otherwise, choosing to take the day off will cause the game to immediately proceed to the next in-game week and will cause an idol's enthusiasm to automatically increase.

The rank up limit has been removed, and the player is now given 52 weeks to produce an idol unit with the addition of specifying the month.

In the early 2000s, there were arcade games already in use that allowed players to save their progress on magnetic stripe cards so as to continue playing later.

[15] Next, in order to effectively use the competitive culture that surrounds video arcades, Ishihara thought about various themes for the game, including professional wrestling and volleyball.

[15] The popularity of the talent search show Asayan partially influenced Ishihara in deciding on idols for the subject of the game, although he was still unsure if it was the right decision at the time.

Therefore, one of Koyama's goals in developing the game was to restore a community where players would discuss what parts of which characters they like or find cute.

The basic concept of the game dealing with a producer training a prospective idol to reach the top of the entertainment industry was only solidified late in the development process.

The balance between the graphics, music and gameplay system had to be adjusted to lessen concerns about players being embarrassed to play the arcade game.

The idols of Morning Musume were used as an influence to create character types in The Idolmaster traditionally found in bishōjo games.

Their other focus was on allowing players to comfortably play the game and enjoy its various scenarios without the rushed gameplay found in the arcade version.

[15] When developing the Xbox 360 port of The Idolmaster, the characters had to be entirely redone, including the motion capture, which used the same actors as before.

[28] Namco Bandai Games released 12 downloadable content updates between January 24 and December 25, 2007 available through the Xbox Live Marketplace.

[20] The songs from the arcade version were released by Nippon Columbia on a five-part CD series of compilation albums titled The Idolmaster Masterpiece between 2005 and 2006.

[32][33] The songs from the Xbox 360 version were released by Nippon Columbia on a four-part CD series titled The Idolmaster Masterwork between 2006 and 2007.

[37][38] The Xbox 360 port of The Idolmaster sold 25,000 copies in its first week of sale and was the fifteenth best selling console video game in Japan for the time of its release.

[40] The port has been credited with making Japan's ratio of sign-ups for Xbox Live compared to the number of consoles sold as the world's highest.

[2][40] Despite there being a limited number of minigames for the lessons, they are described as having an "abundance of variation" that do not get tiring because of their unexpectedly high degree of difficulty.

[40] Dom Nguyen writing for Wired described the arcade version as awkward at times and felt apprehension about the various touchscreen minigames that "encourage you to fondle the screen."