To address the biggest issue I see in this movie, I have to mention the art style. Most of the time, the CG is god awful to look at. Other times, it's tolerable. It's not even a matter of the dull colors and bland look. That can work to a certain degree in an almost "realistic" type of setting. It's hard to describe. Each human looks nasty, and not even in a grotesque "they're the monsters in this story" type of way, but a "the animators are new but determined to make a movie" sort of way. The beginning doesn't look so awful, but immediately after the market scene, you see a child whose face and how it's animated look like if you take Sid's face from Toy Story but give it a less "clay-like" look where it's at least brushed over and looks soft and give it a 3-4 x's downgrade where it looks like it's lost texture. The coloring and outlining look flat and blunt, to put it nicely. And the design, while probably purposefully made to look unattractive, unlike Sid, just doesn't have any charm.
Unfortunately, MANY of the humans are like this. Not always, mind you. But most of the time. It's like if you took the animated baby that was passed around in email chains back in the day, saw it, and said to yourself "this is actually really good!"
In regards to the other parts of the art direction, the camera work is always really interesting. There are times where it focuses higher at human level to make the fish feel extremely small, while other times, it brings you down to the fishs' height. The song segments, too, also get very experimental with the art change. THAT part of the art direction is absolutely beautiful. It surprised me first seeing this movie just how pretty the art was at these points.
Sound direction was decent. There were times during emotional scenes especially where the ambience made me even more immersed in the moment. I also really love the music. The musical numbers are all very nice. I've seen some people compare the songs to Disney in quality, and I can kinda see it. Only complaint is a few songs didn't really feel like they furthered the plot or really gave us something new about the character, while at other times, the songs did just that.
The characters themselves were great, mostly simple but were still played out nicely. You have your "villain", a bully in the tank who is a flatfish that was previously living in the sea like the main character, a mackerel, who is determined to flop to the sea. They're your two main characters, along with an important secondary character who is a young fish who is inspired by the mackerel, hopeful and kind. I was honestly surprised by how the development for the flatfish went as he was easily an unlikable prick when he's first introduced. The mackerel is kind of your standard "I'm going to beat the odds!" type of character, however, but she's alright. Despite the tropeiness, the characters all served their purpose nicely.
There's also an eel that is like a snake, the lackey of the flatfish. He's in charge of rallying the fish to solve "riddles" each night, where the winner gets to eat a piece of the tail of the fish furthest from the right answer. There's 3 others, too, fish species I cannot remember, but you have a tired and somewhat dumb one, one who's openly apathetic as well as another who's even more-so. Otherwise, those 3 are the least interesting in the tank, while at least the eel is an okay villain with a fun song number.
The sea is within a short distance from the tank, but the issue is the humans which will instantly go after them (and the lid being placed on top at night). The flatfish taught those in the tank to play dead whenever a customer is spotted so that they'll eye another tank, coming back to life when the workers are by themselves so that they aren't thrown out. It made for an interesting set up, especially with the hierarchy in the tank being thrown into question with the mackerel being brought in.
Overall, it's not a long movie, and I think it's well worth the watch. I say that anyone watching it should give it at least 15-20 minutes before deciding to duck out. It's a good movie, like a macabre take on Finding Nemo but "Nemo" is freedom and the journey is without comedy or a completely happy ending.
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