In short, Hydro Thunder Hurricane is fun. Racing around the tracks, avoiding obstacles, other racers, flying off of water falls and ramps, boosting around sharp curves and corners while exploring for the nearest shortcut or hidden package makes for a good time on the water. As of launch, there are 8 awesome tracks to race and explore with many hidden shortcuts just waiting to be used if you're skilled enough to find/reach them, and if you're boat is strong enough to get you there.
There are three different skill levels of boats: novice, pro, and expert. Each skill group has it's own set of different boats with varying strengths and weakness in their stats: acceleration, top speed, handling, and air control. After selecting your boat, you are thrown into the water of your track where you will compete for 1st place by utilizing drafting, boost pickups you'll find scattered along the way, and the aforementioned hidden shortcuts while you fight against waves and water resistance eager to help you lose control. Finishing in the top three of the race will earn you credits that will accumulate to unlock much of the game's offerings, such as additional races, challenges, new boat skins, and, of course, new boats. You also have the ability to unlock extra items just for completing certain tasks, such as earning a trophy in certain maps on certain events and finding all the hidden packages on specific levels.
Single player campaign offers the traditional race of all 8 tracks. There is also the ring master mode, where the objective is to race through the rings set on the track and finish within a certain time limit to determine which, if any, medal you earn. All 8 tracks have three different ring master difficulty settings for a total of 24 different challenges to play with increasing difficulty. Ringmaster mode is a good way to learn the courses and the shortcuts and paths each course has to offer while further exploration allows you to find hidden packages (spinning Hydro Thunder logos) that are scattered across each course that require more than just racing to find. There are 10 packages on each track. Missing rings, or gates as they are called in game, adds seconds to your time trial, depending on the difficulty you play. Each missed gate penalizes as follows:
Novice: +1 second
Pro: +2 seconds
Expert: + 3 seconds.
The single player Gauntlet mode is also time based. Your objective is to race the track alone as quickly as you can using boost pick-ups, boost jumps, ramps, and shortcuts. The real challenge is racing as fast as you can while avoiding the hundreds of red barrels peppered throughout the course that are just waiting to destroy your boat. Makes for an explosive good time, but at least you don't have to worry about getting extra seconds tacked on for missing a gate ring.
The last single player challenge is championship mode, which is the standard multiple course racing tournament where racers will compete for overall point scores to take home the gold.
Even with all the lovely single player content, Hydro Thunder Hurricane also offers online and local multiplayer, pitting you against other human players in all types of boats, racing for leaderboard scores and credits to unlock additional content over time.
Overall, this game has alot to offer, which justified the price tag for me. Fun racing, great graphics and gameplay, and decent but somewhat irritating techno music to polish it off. There's also the very likely chance of DLC in the upcoming months to expand it's offerings, so this makes for a good XBLA game choice.
P.S.- Achievement-wise, this game is VERY TOUGH and most people will not be able to complete it 100%. In order to Bronze and then Gold every event, you will have to do ALL 8 tracks on EXPERT in one run-through for each of the game modes (you can however, restart each individual event, and quit out and return later. But still, that doesn't make it any easier.) ~~Thanks to McGubbalo for this difficult achievement warning. COMPLETIONISTS, BEWARE!