I really think that the HD version has great gameplay on the daytime levels, but the Werehog levels were very long, monotonous, and got tedious very quickly, not to mention breaking the flow of the game.
This version was of course toned down technically, but was it any more or less fun than it's big HD brother? SEGA outsourced the Wii version (a PS2 port was also created) to a different development team (I beleive it was Dimps?). 'Unwiished' was created as the Wii couldn't handle the Hedgehog Engine and the gameplay that came with it in the HD version. It also ran on SEGA's (at the time) new Hedgehog Engine. The HD version has better visuals, slightly narrower level paths, and uses better visuals.
The two versions both have the same ideas of gameplay, but are different in execution. There's the HD version on Xbox 360 and PS3, and the SD version (commonly referred to as Unwiished) on Nintendo Wii and Playstation 2. I thought I'd create this thread as I'm quite curious for the community's opinions on these two different version of the same game.