>>40019252Nothing, it's surprisingly better than Sonic Adventure 7 in fact.
Jokes aside, it's incomplete. They released the game too early and so it doesn't have all the content it was supposed to have, and most of what's there is completely broken. It's one of the things that ruined the series' reputation the most and SEGA learned the wrong lessons from it. They didn't realize the problem was the rushed release and not respecting their development team, instead they decided that everything the game's creator did for that game (and thus everything before it) was inherently bad and strayed away from most aspects of the series, going for a completely new direction. That's not to say they didn't have bad games before, or that they didn't have good games after, but now they're afraid of letting the series be what it was supposed to be (Mania worked for the most part at least, and Forces was the first time they allowed themselves to try again, even if it was yet another failure) and they lost all ambition soon after the development of the next game started (Unleashed was still very ambitious, but you can tell something changed during its development).