This defiantly is an underrated Sonic game.
the good-
looks great, runs fast during the day, many new moves, underrated where hog stages
the bad-
cannot move camera in any way
the story is the same as most other sonic games, get the chaos emeralds. However you have to also bring back the memory of a new character called chip. you also have day time sonic stages, and night time not sonic stages.
the day time levels play are extremely fast and look beautiful! unlike past games in the series, the frame rate is excellent and does lag at all when you go fast, lose rings, etc. I almost have no problem controlling sonic, and the camera moves swiftly and is great. there are also new moves, like the boost to run even faster, and the drift to get around tight turns. the homing attack and light dash make an appearance as well.
you might be thinking, " if those levels are so great, why how is the game underrated? " the answer would be the where hog. the levels, are not as good as the normal sonic stages, but there not as bad as what I have heard. the control here is also pretty good, however you will fall off of platforms and fight enemies a lot. these levels are longer the daytime ones, because he is so SLOW! even while running (tapping analog stick twice in one direction), he's extremely slow. the camera can also get annoying, as you cannot rotate it.
I say its the villages that hurt the game the most. unlike the next-gen versions where you Rome around in a small village, you select a somewhere to go and you talk to people until you get an item. its extremely boring and my lest favorite part of the game.
despite all the games flaws, this is still a great game that I recommend to sonic fans and fans of beat-em-ups.