Now this is a real Sonic game. SEGA should continue following Mario's steps in order to make good Sonic games
First of all, it can be said that Sonic Colors is inspired by Mario Galaxy, just like Sonic 4 was created on the basis of NSMB (DS/Wii). I would have to congratulate SEGA for that, because they stopped working on random and supposedly innovative stuff like the Werewolf in SU or the sword in the BK, but they followed an already used and successful recipe.
Even though Sonic Colors is not one of the best platformers and cannot reach the amazingness of DKCR or SM Galaxy, it is the best 3D Sonic game of the recent years.
Advantages:
1) Great use of the 2D gameplay. While in Sonic Unleashed 2D parts consisted of nearly the 1/5 or 1/7 of the actual time and space in the game, 2D is definitely longer and broader than the 3D parts in Sonic Colors and undoubtedly this is one of the best features of the game. Sonic is a character for a platformer not a racer and he is best used in 2D environments.
2) Nice and simple story, not some boring stuff with idiotic dialogues like in Sonic Unleashed. The cinematics are tolerable and the new voice of Sonic is decent unlike the one in SU.
3) Fun gameplay. The use of the seven different wisp abilities is fun, even though it is kind of repetitive at some point
4) Sonic simulator: just plain fun
5) Thank goodness the final boss is Robotnik and not some creepy, disgusting giant creature like in Sonic Unleashed. The final fight with Robotnik is definitely challenging and fits well into the game.
6) Nice and simple controls.
Disadvantages:
1) Tails should have been playable in certain parts of the game.
2) The game felt kind of short overall. Even though the number of Acts in total is not small, some levels were incredibly short and an experienced player can finish the game in a few days.
3) The 3D parts were improved compared to the past 3D Sonic games, but they cannot be compared to the 2D parts. I am just tired of Sonic running only forward in small corridors without exploring anything. Still, the 3D parts can be fun and there are a lot of control improvements.
4) The game is really worthy to bear the name of Sonic, one of the most successful platformer characters, but it does not deliver the magic of a game like Super Mario Galaxy.