Having had about five hours in My Hero Academia All's Justice, that's very much the case here, too. The game is optimized for fanservice- letting you feel like you're getting the most out of your favorite characters. If you've walked away from the final episode wishing you had more time with the colorful cast of superpowered weirdos, this looks like that wish made manifest.
When it comes to evaluating anime based arena fighters, the most important factor usually comes down to fanservice. These games are about making you feel like you have a part to play in these worlds, be it by controlling characters during important fights or just getting to hang out with your favorite heroes.
Having had about five hours in My Hero Academia All's Justice, that's very much the case here, too. The game is optimized for fanservice- letting you feel like you're getting the most out of your favorite characters. If you've walked away from the final episode wishing you had more time with the colorful cast of superpowered weirdos, this looks like that wish made manifest.
Even Mineta Is Celebrated

One of the best ways the game does this is with the Team-Up Missions. These are basically fun filler episode type content- letting you explore the city in a more RPG-like style as your team carries their health between fights. They're also great for how they mix up the game's combat system: in one Team Up mission, I had to fight the entirety of Class A-1 as Deku, with conditions like no jumping or no guarding for certain fights. In another, UA High suddenly decides it's a good idea to resurrect Shigaraki with AI. It doesn't go well.
Getting to play as all the heroes in this mode is really fun because they're also designed to interact with the overworld differently. Deku can swing around like some kind of arachnid based humanoid, while Iida has one of the best sprints to run around with. Admittedly it's not like it's a true open world- you'll quickly run out of things to do besides the objective. But still, if you've fantasized about attacking random people on the street as Deku, it's a fun space to mess around in depending on the chapter.

There's also the new Hero's Diary mode, which might be the greatest humanitarian aid I've seen for fans of non-major characters. Basically, Hero's Diary is just a short story for each of the 1-A kids. It genuinely feels like the kind of thing you'd get as a bonus in a manga: in Mineta's episode, he's simply trying to pick up chicks. This isn't some spiritual redemption of one of the most reviled My Hero Academia characters, it's just watching him get to be silly without the fate of the world hanging in the balance.
Gang Orca Supremacy

Of course, the highlight of My Hero Academia All's Justice is still the 3v3 arena combat. This feels like fanfiction made manifest- where you can just grab from a very extensive list of characters from across My Hero Academia and team them up for no reason other than vibes. Why are Gang Orca, Lady Nagant and Camie hanging out together? Because they're all the coolest looking characters, says I. And they have command grabs.
Characters are simple enough that you can pick them up with relative ease. If you wanna play as Lady Nagant, all it takes is one quick skim of her movelist to know she's got two ammo types and maybe three matches at best before you figure out how to stop Mineta from smothering you with his balls. Compared to more complex fighters, it never feels like it takes too long to get to "the good part".

But that doesn't mean they're shallow, either. Bakugo basically having his own Demon Flip is not something I thought arena fighters were capable of, and ending your combos with a charged shot from him to clip them one more time as they go flying is genuinely cool. Similarly, it feels like Rising Actions are satisfying for both the eyes and the brain: on one hand, the cut-in animations are some of the most polished visuals I've ever seen, and on the other, the in-game abilities like adding seeker missile follow-ups to Bakugo's combos suddenly make him feel incredibly sauced out.

If you do come from more traditional tag fighters there's even a little bit of universal sauciness: Canceling attacks into rising actions always feels good, as does comboing into a super. Sure, it's not incredibly elaborate but it does help shake off some of the feelings of dealing with a simpler system.
It's Not An Ending

Basically, if watching the ending for My Hero Academia has given you a hankering to stay in that world, you'll want to check out My Hero Academia All's Justice. It's a high amount of fanservice in a pretty compact package, be you someone who's looking for more story content or someone who just wants to see cool superheroes throw down.
Whether you're looking to recreate anime fights or even promote the agenda that Gang Orca clears All Might, this one is for the Plus Ultra fans when it drops on February 5th.