If you enjoy incredibly difficult games you'll like this. If not don't buy it.
1: I gave the game a 5.0 only because in the beginning it has a great deal of fun things to do, nice graphics and I actually liked the transformation Sonic takes on.
2: The levels and rings: the main problem I see with this game is that as with many PS3 games, the game immediately becomes too difficult. Very little reward for accomplishments, and the levels are blatantly too difficult to navigate, Sonic constantly gets hit losing rings which get thrown obnoxious distances from him making it hard or impossible to for you to re-collect them, so he often dies very fast.
The levels are too dangerous too quickly leaving you no where to go, and falling off constantly. A game should be fun not infuriating, otherwise there is no reason to want to play the game. In addition I find that for children this game was way too difficult and the children were very disappointed.
I stopped playing and so did my kids, too bad it could have been a good game.