There isn't really a long term objective at play here. The show is basically a slice of life anime looking at the lives of idols work towards simply gaining exposure and make their mark in the idol world under their studio 765 Production, and as idols they find themselves eventually taking up a wide variety of jobs with the help of their Producer. The girls don't have a long term objective they're trying to reach like performing at a popular venue or anything. Some plot points will build up in the background for later episodes to focus on, but most cases here are presented in an episodic fashion. Admittedly they kinda feel rather directionless throughout this until they start to take off later on, but the show seemed more set on looking at 765 as a group and the members individually. The group gets introduced to some rival figures, but aside from a petty producer equivalent to a malicious Pretty Cure villain, they don't have much competition to note. But the world around 765 is balanced. The world of iDOLM@STER is very peachy, but it surprisingly isn't too afraid to get a bit dark at times of and I appreciated seeing it because there are moments that when they happen can hit you.
A general thing I had a problem with is how shows like this tell you a lot but don't always show the processes behind them. In an early episode we're shown the girls taking professional studio shots to help with their promotions, it's a very simple thing but showed a step in them making a transition outside of dancing and singing practice. The show has a lot of things it wants to look at but doesn't always explain or show the steps they took to get to various points. Sure the show could've benefitted from some long-term drama to engross the characters with but I felt like it plays off its slice of life elements well enough.
This show's primary cast consists of 13 main girls as the idols, the Producer who handles all the booking. They have the complicated task of trying to sell the audience on 14 characters and as expected they did an alright job at it. Everyone will find someone they consider their favorite(s), but it's a large group so some feel noticeably more significant in the group than others whose motivations and aspirations as idols aren't presented as strongly or effectively as they could've. A character's focus episode most of the times introduces their backstory or explores their personality quickly, gives them a brief moment of acknowledgement, and then resolves it just as quickly or never really look at it enough ever again going forward. Xenoglossia was my 1st iDOLM@STER experience and while people may hate it, I honestly thought it did a better job at selling some of the characters here, but nevertheless they're still a strongpoint of this.
To me, not every character NEEDS to be intricately written and not every character will be. The majority of the 765 girls have basic fundamental characterization & situations to explore and some have more in-depth arcs with deeper tones and messages, but I wouldn't replace or remove any of them. While individually some characters falter, 765 works pretty well as a group is pretty fun to follow. Everyone gets plenty of moments to just be themselves on screen and play to their strengths enough to leave enough of a solid impression from each of them. As I mentioned earlier about the world being peachy but dark that also applies to the characters. While the characters could've been given more time to simmer on their issues and kinks. there's plenty of layers of emotion to them made known. I wish the Producer and Kotori got some of that time to get some characterization, but you could tell that they're just there to assist in spotlighting the girls.
Touching on the aesthetics, the art is good and remained consistent through the show. The animation when it came time to see dancing isn't exactly Sunrise with Love Live quality, but fairly solid. And if you wanted to venture into the iDOLM@STER games they showcase a LOT of songs through inserts and each episode having separate songs used for the ED sequences. The 2 OPs "Ready" & "Change" are good selections whose lyrical content feel fitting for the 2 halves of the show they accompany. And the VAs have varying ranges they reach given they're all playing characters with varied personalities, so you may pick up on little things about each like how Ami & Mami share a VA and she handles it well, Chihiya's VA having a pretty distinguishably good singing voice, Miki's VA doing well at conveying her exuberant demeanor, etc.
iDOLM@STER in spite of some issues is a nice look at the idol industry in anime form with some elements glossed up but with it's own pool of depth. It was very fun, and I honestly enjoyed the slice of life antics here more than I did other series like this that I've shilled for...