It goes without saying that if you aren't a fan of The Idolm@ster, then you probably shouldn't watch this. But as a huge fan of the series, watching this was like a no-brainer! When it comes down to the art style and sound, there really isn't any noticeable difference from the anime and the characters are still their bubbly selves with all of the voice actors reprising their roles which is probably important for many.
When it came down to the episodes, there wasn't anything new introduced to the series and they weren't all too special. Each episode starts off EXACTLY the same with
the Producer entering the office and announcing that 765 Pro was invited to the International Music Festival where they'd perform. However the episodes differed after that because depending on the episode you were watching the girls chosen and the story after that would be different. Here is a description of each episode (if you prefer not knowing who's chosen for each episode then I'd stop here):
1. "Honey Sound - Music in the World" - Haruka, Azusa, Chihaya, and Ritsuko are chosen to go to the IMF. There they have a run in with Jupiter who's also competing and after seeing how prepared they are with their performance, the girls start to worry that they won't be able to top Jupiter's performance. Watch to see who wins!
2. "Funky Note - Music is a Friend " - Mami, Ami, Hibiki, Iori, and Yayoi arrive in IMF and immediately want to play. After getting a reluctant "yes" from the Producer, the girls spend the day enjoying themselves. However the next day, Iori wakes up to find that her precious bunny, Charles, went missing during their day of relaxation.
3. "Groovy Tune - Music of Love" - Miki, Yakiho, Makoto, and Takane have decided that they must understand "love" better (mainly due to Miki). So to understand, they chose the Producer to be each of their dates for the day for ~2 hours. However, when Miki see's how nicely the other girls get along with him she starts to get jealous and their nice vacation starts to fall apart.