A mixture of awesome, intense platforming with generic, uninspired platforming.
Let's start with the game's presentation, more specifically, the story. This time around Dr. Eggman has fired a giant laser at the Earth, thus breaking it up into pieces. He does so in order to awaken Dark Gaia, some monster deep within the planet's core. Fortunately, Dark Gaia collapses upon awakening, so Eggman must first gather up the monster's pieces before unleashing its power. Unfortunately, this wasn't the only monster created: thanks to Dr. Eggman, Sonic now transforms in a werewolf like creature called a werehog during the night. Additionally, the Chaos Emeralds have been scattered across the globe. It is up to Sonic to gather the Chaos Emeralds in order to use their power to restore the planet pieces back together. Some have complained that the story is too juvenile (comparable to that of a Saturday morning cartoon), but I don't have any real complaints about it. Heck, I'm just glad that there is no confusing time travel or bestiality in it (though one has to wonder why Eggman did not learn a lesson from Sonic Adventure 1 and 2 about awakening powerful creatures?). My one complaint about the story is the game's new character: Chip, the little fairy-like character who acts as your guide throughout the game. Chip is to Sonic Unleashed as Jar Jar Binks is to Star Wars. Both are annoying characters that most people (including me) hate. First of all, his voice is terrible. Second, his tutorials can be irritating in the beginning. "Press the A button to jump!" "Gee, thanks, I did not know that!" *shaking my head*. Luckily, both of these problems are more or less resolved later on. Chip's voice is something you get to (though never enjoy, to be clear), and his tutorials are not present in all stages. Even more fortunate, Chip is a fault ONLY in regards to the presentation of the game, NOT the actual gameplay. Sonic is the only playable character here (kind of, anyway, but more of that later on), so he is not like, say, Big the Cat in Sonic Adventure, with his own set of incredibly boring stages.
Moving on to more general aspects of the presentation. I really like the game's overworld map, which is a globe. There are eight levels in the game, most of which are based on real world locations, which makes things interesting. Each level contains several stages within it. The dialogue shorty before entering said stages is on the mundane side, but is not a major problem thanks to its brevity. In sharp contrast to the dull dialogue, the awesome cutscenes that come up from time to time are really well done, particularly the opening one at the beginning of the game. There are also a few genuinely funny moments here, such "Ergo" the robot. The game's many sounds, both music and sound effects, perfectly fit in with what they accompany. Neither ever feels out of place. Sure, as aforementioned, Chip's voice acting is awful, but Sonic's VA certainly isn't. Whatever the music's purpose is, whether it is too add intensity to a boss fight, a sense of rush to a stage, or a sense of emotion to a cutscene, it does well. Visually, the game looks absolutely stunning. Granted, the Wii version looks inferior to its PS3/Xbox 360 counterpart, but not by as much as you may think. This just goes to show how it is not always how much raw horsepower you have but rather in how you use it. Sonic Unleashed is one of the most visually pleasing games I've seen on a Wii, roughly matching the Super Mario Galaxy games and surpassed only by Sonic Colors. Sonic Unleashed also has a fair amount of lasting appeal. While there are no multiplayer options or something like mini-games, the main quest itself is fairly lengthy. Add this to the fact that there are things like art, music, and those cutscenes to collect, and you'll be playing this game for a while. To be fair, it should be noted that it is doubtful one will have the motivation to collect every single little trinket, but this will still keep you occupied for a while.
And now onto the most important part of any video game: the gameplay. Sonic Unleashed has two distinct gameplay modes: Fast paced hedgehog levels by day and slower paced werehog stages by night. Let us begin with the former. The daytime stages are an absolute blast, no two ways about it. Dashing past detailed environments at blazing speed while attacking enemies, dodging incoming obstacles, and collecting rings is just plan awesome. Some might call these stages too simplistic, but sometimes less is more. There is nothing like the thrill of making a mad dash for the goal while there are only 10 more seconds to get an S rank. These stages switch back and forth from behind Sonic 3D to 2D segments reminiscent of some of the hedgehog's older games, with roughly 70% of each stage consisting of the former and 30% of the latter. Either way, obstacles come into view long before you reach them, giving you plenty of time to react. Your mad sprint through a level will not be ruined because of some poor level design. All in all, the daytime stages are comparable to shifting classic Sonic into 3D and adding in an exhilarating sense of speed along with some innovative gameplay mechanics (e.g. the quick step, a new move Sonic has that allows him to suddenly shift to the right or left without losing speed or direction).
At this point, even if you have not red the plethora of reviews out there of Sonic Unleashed, you have probably guessed what that one aforementioned aspect of the game is that holds it back: the werehog stages. First, let me just say that the werehog stages are NOT that bad. They don't have some awful camera that only lets you see what you are doing about half the time. They don't have poor controls that make you want to throw your controller at the television. They don't have random difficulty spikes that make you want to pull your hair out. No, nothing like that. In fact, these levels are all right in their own regard. Basic platforming and some combat sequences can be somewhat entertaining, and the added Wii motion controls help spice things up a little bit. However, if I could choose one word to describe the werehog stages, it would either be "generic" or "uninspired." There is nothing here to set it apart from your typical platforming experience. Imagine having a thick, juicy steak for lunch and then for dinner having a cheap hamburger patty from a fast food restaurant. Sure, the latter is okay, but going from one to the other is a bit jarring. In the same way, the werehog stages pale in comparison to their daytime counterparts. To make matters worse, there are more standard werehog stages than standard Hedgehog stages. For each level, you have one standard daytime stage plus these mission stages, which are something along the lines of "Get to the goal without taking damage!" or "Collect 100 rings!" The werehog, however, gets a full three to five standard stages per level. When you add this to the fact that werehog stages take much longer to completer than their daytime counterparts (roughly 2-3 times more), you are going to spend more time under the moon than under the sun in your initial playthrough.
CLOSING COMMENTS: Sonic Unleashed is a game that is somewhat difficult to score. Individually, the gameplay of the daytime stages would be around a 9/10 whereas the nighttime stages would be roughly a 5/10. So, averaging these two together comes to a 7/10. I averaged the two evenly because although I have noted that the werehog is more dominant that the hedgehog in the initial playthrough, there is little incentive to replay nighttime stages after completion (even the opportunity to earn bonus stuff isn't enough to want to experience them twice). Conversely, the daytime stages have high replayability in trying to get that perfect S rank, finding hidden paths/goodies, and just for pure fun. When one factors in that the game looks and sounds great with an overall good presentation (save for a few nicks), the score is raised to an 8/10. Had Sonic Unleashed consisted of less werehog stages and more hedgehog stages (or perhaps even solely of hedgehog stages), it likely would have been almost as great as a game like Super Mario Galaxy.