We're rather looking forward to Sonic Generations and SEGA have finally lifted the lid on the funky StreetPass features that'll be incorporated into the 3DS version of the game, revealing that there'll be up to 100 missions to unlock by letting your portable consoles virtually shake hands.
SEGA has revealed that upon StreetPassing another Sonic Generations player you'll be able to exchange profile cards that basically dish the dirt on how much of a Sonic fan your new chum is. Your player progress is displayed here, along with you preference for Sonic's many, franchise-ruining, friends.
On top of that, there are 100 missions to unlock. When your 3DS bumps wireless uglies with another Sonic Generations-sporting 3DS, the new player will be logged and, when you click on their name in the log, you'll be able to play through one of the levels that they've already completed. The challenges vary from defeating a certain number of enemies, to different takes on in-game levels.
If your 3DS is the reticent type, though, you can still unlock these levels via Game Coins. [via andriasang]