lol
Well, Wii Sonic Unleashed's daytime levels are kind of short, depending on if you can find the shortcuts / alternate paths that give you the best times or not. There's a bit more variety, path-wise, and sometimes it might be hard to catch them because you're running so quickly.
The nighttime levels can take you from 7-10 minutes per act (you get like 2-3 nighttime levels per daytime level lol), but they're more exploration based if you wanna get S-ranks on everything (find as many exp boxes/enemies and rings, complete it by 7-9 mins) But if you rush through them, it'll take like 4-6 mins per night-time level.
Bosses are waaay more variable in Unleashed, of course. Though you also have to deal with night-time bosses, too, which are kind of like... Zelda bosses, if you've played Zelda games lol.