Jogo bastente único e divertido. O gameplay é extremamente simplório, mas funciona e é bem bacana, principalmente considerando que é um jogo de GBA.

Surpeendemente, a narrativa desse game é uma das melhores da franquia. Os diálogos são divertidos, bem escritos e a interação entre os personagens é ótima, só não gosto muito das caracterizações do Shadow e da Amy.

O problema desse jogo é o QUÃO repetitivo é o modo história. Sério, beira o surreal de tão repetitivo e de quão artifical são as maneiras que o jogo se utiliza para prolongar sua duração. O modo história desse game é pra jogar um vez só e nunca mais.

Por outro lado, a customização do Emerl é bastante intuitiva, o jogador se apega ao robô ao treiná-lo durante toda a narrativa. Montar o fighter perfeito e usá-lo é mais divertido do que aparenta.

Se não fosse pela tediosa repetição, Sonic Battle seria um jogo nota 8 facilmente.

It's... ok. Really the most I can say about this game. I should say that this is all from a single player perspective, I have sadly never been able to play this game with other people, despite it being a fighting game.
I think the core gameplay is nice, having a basic attack, a heavy attack, a dash attack, an air attack, an upper, a kind of weird homing in attack you can use in certain situations, and various special attacks. The game doesn't really come off as hampered from the lack of buttons imo, my main issue with the gameplay is the lack of interesting movement options, which is a shame due to the size of the arenas the fights takes place in. Each character feels unique to play which is nice, but there's obviously some balancing issues here (Cream is ridiculously good compared to the rest of the cast for example). A cool part of the game is that the main character, Emerl, gets to use traits from every other character, so you get to pick your favorite tools and combine them into one super-character. Though sadly, by the time you've got enough skill points to use everything you want (skill points being increased after each fight, they're the game's way of not having Emerl be stupid broken from the get-go, limiting what you can have on him at once) the story is pretty much over. Also annoyingly there's no actual way to get one skill over another (outside of character), it's not based on how much a move is used or anything, you just have to get into a battle with the character you want to get something from and pray you get the one you want.
The main story is... pretty fun but it has a few critical issues. Sometimes it can just drag on and on, like, you'll finish a battle that has 3 lives for everyone, and then have to do an exact repeat of that fight with 5 lives. It just gets exhausting.
Secondly, the AI is very susceptible to getting caught in loops (mainly with special moves, but can be done with some other moves like Rouge's air attack) which obviously makes the fights less engaging, though the AI will automatically block a special attack if you use it too much against them (this is limited to one at a time however, so if you alternate between two the problem is still very much there).
The story is, like, stupidly good for this GBA spinoff fighting game, but I don't want to reveal too much. Basically it centers around Emerl, an ancient robot that Professor Gerald had worked on before Shadow, with him interacting with different characters in the 8 campaigns. There's ones that are kind of just there like Knuckles', but if you get through all of them the story in this game is really one of the best out of Sonic.
Aesthetically I don't have much to say but yeah it's excellent. The portraits are all super sleek and there's a reason the sprites from this game were used in all those flash animations. Music is good, sometimes the GBA soundchip makes it ear grating but sometimes it really works (go listen to Battle Highway).
I don't really know who I'd recommend this game to, Sonic fans for the story, sure, but none of the elements from the main series really work their way into here. This game is very odd for a fighting game, so don't know if I'd suggest it there either. Just play it if you feel like it, I guess.