How can you eggman land on sonic unleashed

You have to complete the game first. The first time you go to Eggman Land you will go straight to the stage. The second time you go you will actually go to the 'capital' where you can buy souveneirs and food for the achievements and stuff like that. Like every other city stage, only it's smaller and not as many people to talk to. If you're got the Xbox 360 version, talk to EVERYONE there. it's worth it, trust me.