Ah, Forces. A game that failed to meet even my rock-bottom expectations. I was turned off from the very first teaser, and everything revealed after only confirmed or exceeded my worries.
Modern Sonic's gameplay is a mess. The boost gameplay has managed to get even worse, with levels being shorter, more linear, and more automated than they've ever been. I've argued for years that it's a rotten style that we desperately need to replace, but I'm still shocked at how far it's fallen; I could at least understand some of the appeal when it was big, fast, and flashy, but now it's just completely rotted out.
Classic Sonic continues to prove that "classic" is just a cheap gimmick in Sonic Team's eyes. There's literally no reason for him to be here other than Sonic Team being able to say "hey look Classic Sonic is here! From Generations! And those other games you like!". The closest thing to a narrative justification for his inclusion is that he cheers up Tails, but this amounts to him showing up, being a Sonic, and this apparently cures Tails' depression instantly. And his gameplay is, of course, still trash. They've apparently tweaked some values since Generations, but they still haven't bothered to figure out how classic Sonic gameplay actually works nor do they have the guts to genuinely try to come up with their own take on classic Sonic, so it's basically the same broken mess again.
The Avatar character maybe manages to be the least awful of the three styles, but that's no compliment. As a player-created character the customization options are pretty weak, with the focus largely on unlockable clothes and accessories that tend to result in characters that look overdesigned and out of place, while options that more properly define a Sonic character's design like species, hair, and color patterns are disappointingly limited. Their gameplay is little more than a stripped down version of Modern Sonic's; swap the homing attack for a no-less-automated grappling hook and the boost for one of a few wispons to chew through excessively large hordes of passive enemies and that's about it. The wispons are largely interchangeable as weapons, and the wisp powers associated with them are a crapshoot; some are decent, some are bad, and if you choose the wrong wispon for a level, well, you get nothing, sucks to be you. And of course the tag-team gameplay fixes nothing with either character.
And the story is no better. It's an absolute waste of the "Eggman wins" concept, an idea that you can only really try once; instead of getting a world that actually feels like Eggman has taken over, he gets pushed entirely into the background in favor of the dull and unfitting "war" theme and the complete non-entity that is Infinite. And that guy, fuck me is he bad. Nothing more than the most generic edgelord villain personality combined with a power that could have interesting uses but in practice is only ever used as brute force. We don't even get anything close to a proper motivation until Shadow's campaign, and the answer still doesn't make any goddamn sense. They couldn't come up with even one interesting idea to do with this guy; he shows up, he's evil, he beats you, you beat him, he dies, the end. Not that anyone else is much better, of course; Eggman, again, is pushed entirely into the background, Modern Sonic just does the usual Sonic heroing thing with his early defeat never actually meaning anything, Classic does nothing, anything interesting with Tails ends as soon as it begins, the copy villains are a narrative bust, and most of the resistance just stands around talking at you the whole time. The Avatar is the closest to having any kind of actual story arc, and that just amounts to "I'm scared and I suck but I'm gonna try hard and Sonic believes in me so now I'm strong!". Except it doesn't even land since you can already do crazy grapple hook flips and take out tons of enemies from the first level and the only indication that he's not already basically a superhero is that he stumbles in one QTE.
It's just, like...everything is bad. It's not an utterly broken game like '06 or RoL, but from start to finish every choice they made was the wrong one. I can only hope that Sonic Team's learning the right lessons from this and from Mania, but given they made this mess in the first place, I don't have much faith in them figuring it out.