How does Sonic Unleashed have more incommon with the Sonic Adventure titles than Sonic 06 and what replay value does it have

sonic unleashed has a couple things in common with sa1 but not really sa2 not much if you get it for the wii but a bit for 360/ps3 I suppose that Sonic Unleashed does have a sort of related storyline towards Sonic Adventure 1. Sonic Adventure 2 does have a way different storyline.