I don't know why people praise Super Mario 64 so much but don't like Sonic Adventure. (Okay, though I've played Sonic's 3D offerings, I've only played a few minutes of the first Sonic Adventure on Dreamcast and the voice acting is atrocious, but still.) They say it's a bad transition into 3D unlike Mario's transition.
Now, Super Mario 64 is a great game, really it is, but when it came out I was mourning the loss of what I liked about Mario games. Where are the bricks and blocks? Why are there so few Goombas? Why can't I kick ricocheting Koopa shells around? Where's the Fire Flower? Why am I spending more time punching than stomping? Where are the Koopalings? Where's Yoshi (I mean other than the roof) and Luigi and alternating two-player? Now instead of dealing with obstacles as they come and running and jumping to the end goal before the time is up, I'm now looking for Stars. There is nothing wrong with the new formula, and I do like the game, but it sure is a departure from any previous Mario game.
Then you look at Sonic. You're still running to the goal, at least when you're playing as Sonic. So they kept that part of it. When you're playing as other characters like Knuckles in Adventure 2 and have to slow down to look for stuff, why is that a bad change when Mario is now also looking for stuff? I don't get it. Is Sonic's transition to 3D so much more different than Mario's transition into 3D? Do non-Sonic characters really suck so much (other than Big the Cat)?
Perhaps since everyone felt Super Mario 64 was a great game that they felt it was a good transition (whatever was missing didn't matter) that they felt every good franchise should be able to make it in 3D, that when Sonic Adventure came out there were expectations that weren't quite met and all of the sudden it's not as good a game. Could that be it?
I could be missing something, admittedly. I welcome you to prove me wrong, because I'm enjoying the Sonic 3D games and apparently I'm told that I shouldn't.