In-game, his jumping/rolling sprites are used for diagonal movement instead. Unfortunately, the physics are far from perfect, resulting in some odd collision detection and making the final boss rather easy. One big difference is that the Special Stage rings take Sonic to the spelling challenges the Chaos Emeralds (of which there are only three) are instead awarded for beating bosses, with the final boss giving up the Master Emerald. Unlike Sonic X, which was a reskin of another game, the Didj's Sonic couches the educational stuff in Genesis Sonic-style gameplay, bringing over numerous graphics, sounds, enemies, and items from those titles. Sonic the Hedgehog was the second of two Sonic games released for LeapFrog systems, following Sonic X, and like its predecessor contains educational aspects (in this case, spelling).