The MAIN main character, Narita Top Road, is the strongest of the main three thanks to her emotional struggle being written well-enough. However, while the foundations are there, it ended up feeling weak since her supporting cast isn't fleshed out. It still had its moments where you can tell what the writers were going for, at least.
Admire Vega's whole situation felt asinine to me and made her not enjoyable throughout. This wasn't wasn't helped by it being very obvious how it was going to end up for her. I will admit that I still like how it happened...but even then it should've happened in time for her to flex it. Plus that would've stopped her from repeating herself up to the end. Actually seeing it would've definitely helped me like her more.
Opera O is unsurprisingly a joy and the best foil to put next to these two, but she definitely felt more like a secondary character than an equal. But maybe that's for the best. I think the point of her (and a great aspect of her) is that, unlike most other horse girls, she doesn't have anything to flesh out. I think that gave the writers a hard time making her impactful enough to fit as a main character as advertised, though.
Another issue is that the supporting cast is basically non-existent — besides Top Road's trainer (who is good). The rest of small supporting cast that actually is there felt very one-dimensional and not impactful to the main trio. And they're all you have. I ended up missing when the first two seasons gave small one-line roles or mentions to the other unimportant racers, because they get literally nothing here. It made the world feel surprisingly empty. Of course this is probably because this was only a four-episode ONA and all they wanted to do was highlight the main three, but that doesn't stop the experience from being weaker as a result.
For what it's worth, I think this anime still works as far as highlighting what makes Top Road, Admire Vega, and Opera O notable and likeable characters (at least if you haven't met them in the mobile game already like me). It just does it in a way that isn't interesting, especially after watching the previous seasons. At best I'm left to imagine the best versions of these character (which, hey, I'll take).
