Cheapest I've seen this; elsewhere:-
Amazon UK £29.99
The HUT £31.55
Sonic is speeding onto Kinect for Xbox 360 in an action-packed experience unlike any other!
Become your favourite character as you jump on your board and get ready to compete in exhilarating, adrenaline-fueled races against tough competition.
For the first time use full-motion body control to twist and turn your way through a range of visually stunning courses. Hi-octane fun for 'riders' of all ages, Sonic Free Riders brings extreme fast-paced boarding action in a main event you won't want to miss!
Kinect controls - Turn, twist and jump, as you speed your way to the finish line! Use your whole body to take full control of a variety of hoverboards and bikes
Easy to pick up and play - Fun for all ages! Compete with family and friends in single and multiplayer modes, each with their own unique race rules
Customization - Customize your board and bike with unlockable gear and unlock upgrades to increase your speed, skills, and special abilities
Unforgettable Characters - Race as Sonic, Tails, Dr. Eggman and more, including your personal Avatar!
Pick-ups & Weapons - Add even more excitement to each race with item pick-ups! Reach out and grab a variety of rockets, bowling balls, traps and more to knock your rivals off-course. Throw, shake, or swing to launch and give yourself the competitive edge
Over-the-top Environments - Race through epic settings including sun-drenched resorts, deep winding canyons, glimmering waterfalls and majestic ancient ruins, each with their own unique traps and surprises around every corner