After reading Gamespots review for this game, I must say, I am outraged.
When its daytime, the gameplay is just fun. I have no idea what gamespot is talking about. The controls are VERY responsive and the new ring energy realy makes the game alot more fun. The drift is an excellent move, along with the sidestep, and they make running at 300km/h very fun. The level design is also excellent, and you switch through 3d and 2d thourhout the level. The levels have lots of variety, one moment you'll be dodging on rails and the next your running up walls or on water, it is very, very fun. The new quick-time events are also welcoming, and are by no means a hazard or death trap. The Boss fights are a blast and the difficulty is just right. Sega should have made the whole game this way.
When the sun goes down, you are turned into a werehog. I've heard alot of review bashing this and saying its slow, boring, monotonous, and totally a drag. I expected it too, but I must say, it is not. It still isn't NEAR as fun as the daytime levels, but its still pretty decent. The platforming is like anything you would see is a game like Banjo Kazooie and Super Mario, and are challenging at times, keeping you on your toes. The combat however, is the best part of nighttime. If you like Ratchet and Clank or Donkey Kong 64, you will LOVE the combat. The enemies are sometimes challenging and always keep you alert. You also have access to different combo's which keep the combat fresh and entertaining. I must agree with gamespot on the checkpoints though, they are pretty bad. SOme of them are set just before a huge brawl, so you'll reach it, brawl alot of baddies, then go on to platforming, fall in the water, then have to brawl everybody again.
Sonic unleashed may not be the game everybody was hoping for, but it is by far worth a rent. Do not listen to gamespot on this, it is very fun, and deserves much more credit than it has gotten.