Sonic Unleashed is built on a powerful new " Hedgehog Engine " , which introduces seamless 3D to classic 2D camera transitions, whilst delivering a rich and expansive world with multiple paths to choose from. Under development for three years, the Hedgehog Engine produces a visually rich next generation look and feel with elements of classic Sonic gameplay mechanics. The Hedgehog engine will help re-define the gameplay experience for Sonic fans and newcomers to the franchise alike.