With some patience, you'll find a very rewarding, cohesive, and surprisingly original experience in Sonic Riders.
The good stuff:
The sheer number of separate, original mechanics is pretty amazing and stands as a measure of both the creativity of the developer and their ingenuity in making them all work. You won't find a game quite like this anywhere else, that's for sure. Air management, tricking, turbulence, shortcuts via jumps and character skills, and even the running start are all great, novel ideas that were implemented well. Once you're proficient at the separate skills involved, everything gels together into an impressive and deep racing experience. Special props go to the guy who thought up the turbulence element, which is by far the coolest of anything they put in this game.
Also, 14 tracks is a pretty good start! Most of the tracks are balanced pretty well for each character's shortcut abilities, and they're just the right length. Races really take place within the environment, rather than just around it like F-Zero GX or some other futuristic racing games. You're moving pretty quickly through them most of the time; the sense of speed is excellent and I'm glad it got some special notice in Mr. Navarro's review.
It's important to mention that the game looks fantastic for the platform generation. Character models are diverse, detailed, and have unique and fluent animations. Gears have unique shapes and, for the most part, look just plain cool. The tracks even prettier; they're immersive, vivid, and mostly very clean looking.
It's good, but… :
There's also a whole lot of unlockable characters and boards that add to the number of ways you can play the game. However, there's also a good portion of those boards that are pretty useless. Makes you wonder if the devs got lazy here…
Mission mode is a good way to add some single-player hours on to the game, but some of them are just collect-fests, while others feel like you've played them 15 times before. Only the more hardcore players are going to try to get gold medals across the board here.
The not so good stuff:
Sonic Riders is not the kind of game you pick up and play well the first time you try it. In that respect, this is no Mario Kart. It's frustrating for beginners mainly because it's way too easy to run out of air and it's not easy or obvious how to gain it back. This hurts the multi-player portion of the game too because it's just not easy enough to learn without some practice.
At the same time, the AI is too easy for players who DO have the game figured out. Once you start beating the AI consistently, you'll find that it's pretty hard to lose.
Also, story mode is pretty terrible. The script is 3 times worse than that of any Saturday morning cartoon and the voice acting is garbage. Play though it once just to beat it, and you wont need me to convince you not to do it again.
What it needs most:
A better tutorial. The video is a start, but it would be much better if you could practice the race mentioned before. Trial by fire isn't any fun for the casual crowd this game is marketed towards. It would also make multiplayer much more accessible and competitive.
A more fleshed-out Grand Prix. The longest single-player experience is 5 races. This is over in about 20 minutes, max. It's just too thin to provide the lasting replay value any racer should have.
Again, great effort from Sonic Team. There's enough great ideas here for more than one game, and it looks like with the release of Zero Gravity next year that Sonic Team is looking to expand on the serious potential that Sonic Riders exhibits in its fast and exciting gameplay. Hopefully, they'll find a way to do that without frustrating the younger and more casual gamers who enjoy Sonic just as much as those who played is 15+ years ago.