I wasn't originally planning on watching this movie but it just sort of happened. In any case, this movie is a follow up to the original Idolm@ster series. Basically, the busy girls are reunited for their first ever live arena concert. Given the size of the stage, 765 Pro has decided to add backup dancers as well. This movie follows the group as they prepare together for the concert, and encounter some minor bumps along the way.
This movie is strictly for those who enjoyed the original TV run. If you didn't particularly like the series, you're not going to be enamored with the movie either. And given the short duration to girl ratio, unless you're rooting for either Miki or Haruka, you're going to be disappointed in regards to character screen time as well.
Animation:
The animation style is very similar to the original series. The only noticeable update I could find is a slightly less saturated color palette, following industry trends I guess. Expect crisp lines and nicely drawn backgrounds. This show is fairly innocent minded so aside for a water gun fight, don't expect much in either the action or ecchi department. Annoyingly, there is CGI usage, significantly so during the actual arena concert; this was unexpected and really poorly done as the frame rate noticeably decreases during camera panning.
Sound:
If you like insert songs, then this is for you. This category is pretty much completely in line with the TV series with returning cast members and similar BGM. In addition, you get a even more faces and voices to match with the backup singers, just in case you weren't overwhelmed already.
Story:
As mentioned, the story follows the girls as they prepare for the arena concert. It gives the show a chance to show how much the girls have improved as the backup girls constantly have trouble keeping up with the true idols. The first half of the movie is pretty much a refresher on the girls as they prepare at a retreat. The second half gets more intense as more problems arise. Ultimately, the issues are resolved and the show concludes with the arena concert. As with the TV series, don't expect any real serious threats or plot twists.
Character:
The characters are as you remember them, with a lot of focus on Haruka, who is appointed the leader of the group for the concert. Don't expect any development or growth, just more of the same.
Value:
If you still vaguely recall the original cast and have two hours to kill, this isn't bad but there are probably other things out there more worth your time. Obviously, if you absolutely love Idolm@ster then by all means go for it.