All right. Since fate has seen fit to gift me with this early copy for... some reason, I figured I should dig into it. So I've played for about three hours now. And after that time, I'm actually upgrading my opinion of it a bit... but with a lot of reservations.
The game gets off on the worst possible foot with it's intro section (the part I played earlier). It's primarily four very tedious, very blocky 2D segments, with a couple of combat rooms and two autorun speedway bookends. It makes for a terrible first impression, especially because it has some atrocious performance and framerate issues. (And also my aforementioned cut scene glitch.)
After that, you're dumped into a big hub area. This is that blocky-looking canyon area from the animated GIF. From there, you can access the actual proper game stages.
The levels themselves tend to be large strings of traversal challenges, punctuated with occasional "arena" type rooms where you fight a few waves of enemies. I've actually generally enjoyed the traversal segments so far, particularly the Knuckles and Amy portions, which were very climbing focused and reminded me of games like Sly Cooper. The Sonic and Tails areas were more like Ratchet and Clank lite -- consisting mainly of button puzzles and smashing crates. These traversal segments transition pretty seamlessly between 3D and 2D segments, and also occasionally integrate smaller speedway or water running sequences, all of which feels fun, if a little basic. The arena areas feel like an intrusive chore, though, because the combat is very shallow. (And really feels like it could use a proper dodge or block mechanic.) It reminds me of the police-fighting areas in Jet Set Radio Future. You just want to mash your way through them so you can get back to jumping on things.
The hub is actually my favourite part so far. There's lots of gradually unlockable nooks to explore, including the ability to run all over the open water, and new areas that you can open up by building things with the robot parts you collect in the levels. There's also a huge autorun speedway subsection integrated into it, very similarly to the boost boot courses in Ratchet and Clank: A Crack in Time. This segment would be really fun, except that the frame rate during part of it is such a disaster that it becomes almost unplayable.
And that's kind of the issue with this game in a nutshell. If it was patched to hell and running on a more powerful system, you'd maybe have a decent if flawed game... some fun platforming ideas mixed with shallow combat and occasional tedious moments. But right now, on the Wii U, this thing is a borderline disaster. Any area meant to showcase high speed or graphics just chugs like crazy. And any portion that runs smoothly, like the hub or the bulk of the indoor platforming, look like an older gen title, with lower res textures and simple geometry. And this is all without utilizing the co-op feature, which makes performance even worse. There's also a ton of popup, and some weird glitches. (Like my unwatchable cutscene, or that strange segment with Lyric's ship.) It just feels like it was rushed out the door without enough engine optimization or bug fixing. Maybe a day-one patch will arrive on Tuesday, but I'm not counting on it.
It's a shame, because it's clear that a lot of effort and time was put into this project. And the story is pretty enjoyable and well presented, with generally decent dialogue and voice acting in the cutscenes. (Although the actual in-level incidental commentary -- "I think you need to hit that switch, Sonic!" -- is cranked WAY too high and grates at times.)
It never would have been a "real" Sonic game, but maybe with a few more months in the oven it could have been a decent throwback to ps2-era 3d platformers. Instead, it's just kind of frustrating. If you're a fan of the characters or this genre of slower platformer, you'll be able to squeeze some enjoyment out of the good parts, but you'll definitely be shaking your head a lot as well. And for those without those soft spots, it definitely is not worth the hassle.