It is 2-player couch co-op. The screen split is dynamic: when you're close together, it's one screen. When you go a certain distance, it splits up. You can also set it for permanently being horizontally split-screen with player 1 on top and player 2 underneath,
"Whatever Febreze can't fix, a gun will." -- Red Mage Oath Sister: the beautiful Lulu Zealot
I have found the dynamic split screen can be a mess in this game. The distance the camera pans out to is hopelessly distant! If you don't have a 70" TV, prepare to sit 5 feet away. Plus, during dynamic, the camera has serious bouts of wild fluctuation with its splitting and panning in/out etc.
The game is overwhelming at the start with how much is going on and the missions can take 40 minutes to complete... but, it's a fantastic game and should NOT be missed.
"Must be glorious to have such a happy knack for clarity and concision."