So I've been playing the PC version and apart from something odd in Chemical Plant Act 1, the game runs pretty well. I'm running a AMD 5770 graphics card, and after setting shadows to low and disabling AA, it runs pretty well.
The keyboard controls, though... I get the feeling that Sega just let an actual hedgehog walk across the keys when they assigned those. Plus you can't assign anything to Shift, Control or Alt either. Ah, well, I bought an Xbox 360 controller, I've got enough consle-ish PC games to warrant a proper console controller now. The game plays so much better with a controller.
EDIT: Ah, darn it. Wrong thread. I thought this was the OT.