I'm fine with the new designs honestly. I really like Tails, and the rest I got used to but I'm still a little iffy on Knuckles. But, since it's a spin-off, I don't make it a huge deal for me in the end.
The only problem I have is how they handled the game itself. Especially how BigRedButton fell apart during development. I'm disappointed how some important employees left, Christian Senn even more so (he may have been fired against his will). Granted, there's many factors that caused this, and they probably have their reasons for leaving. However, a situation like this shouldn't even happen in the first place, considering how much hype they put into the game.