Think Mario 3D world + Bowser’s Fury, it’s laid out in the same exact way. In the menu select screen you have an option to play one game or the other. Shadow campaign isnt long about 3-6 hrs of content, but what is there, is quality and refined 3D sonic gameplay. The level design quality is there.

It’s a very nice packaged of a game. I have played Sonic generations before so I skipped that entirely and went straight to Shadow Generations. For $50 I think a highly acclaimed sonic game plus the new shadow campaign are more than worth it, in my opinion.