I think the last Sonic game on the Wii used Havok, and I know Super Smash Bros Brawl used Havok also. Also, if the PS3 and 360 version of the game lag but the Wii version does not, I'd expect the game to look VERY different on a graphical level. Then again, Sega and Sonic Team have not made a good game in years, so perhaps they really are that bad.
The Xbox 360 and ps3 one use the Hedgehob engine, which uses latest gen. But it lags like a beast both the original sonic and this 1. I don't kno why they made the same mistake twice and didn't use the WII engine.
Reviewers said they can barely tell the difference its just a little more crisp. As for fun factor the wii version has the advantage with motion added to the game.
Whats funny is that the 360/PS3 one was made by the official team, and the wii one was made by a separate team
Its just the engine from sonic and the secret of the rings upgraded.