Before Sonic & Sega All-Stars Racing arrived on iOS back in 2011, the App Store had been lacking a decent mobile kart racer. However, with its intuitive controls and broad cast of characters plucked from Sega vast library of games, this light-hearted racer did a fantastic job of filling the App Store's Mario Kart-shaped void.

Today see the release of Sonic & All-Stars Racing Transformed, the shape-shifting sequel to the abovementioned iOS and console hit. The star-studded character roster of the previous game returns, including Sega celebrities like Sonic's fox pal Tails, Ulala from Space Channel 5, and Ryo from Shenmue.

While the faces may be familiar, the karts themselves have undergone a major overhaul. When the track demands it, each vehicle can now morph into a pint-sized plane or speedboat, allowing you to ferry your driver to victory over land, sea, and air.

I went hands-on with Sonic & All-Stars Racing Transformed over the Christmas holidays, the results of which can be seen in the video below. Stay tuned for the AppSpy review.