Not only is this the second part of Sonic 3, you also get to play as Knuckles! Knuckles has differnt abitlies than Sonic. For starts, he can climb things and glide for long distances. Very fun and challenging Sonic platformer. Get board with the levels but still wish you could play as Knuckles? That's fine! Becaus it also attaches to Sonic 2 and Sonic 3 so you can play as Knuckles. A nice added bonus which takes this game far!