Valve has given CVG the full lowdown on the the co-op campaigns in Portal 2 - and it's exciting stuff.
After checking out a behind-closed-doors preview of the game at E3 last week (which you can see a video of here), we caught up with Valve's Erik Johnson.
He explained that split-screen will play a major role in Portal 2 - both on a single TV and online.
As you might expect, each player will be given a specific colour for their personal portal - while co-op levels will be separate and "pretty complicated".
"We're going to have two-player co-op, so you can play with a buddy," explained Johnson.
"It's a totally separate set of levels. Fictionally, it kind of fits inside of the single-player game but there are custom levels that tend to be pretty complicated.
"You don't play as Chell in co-op, you play as these two little robots because you're going to get cut in half by lasers and crushed by crushers - and robots are a little more appropriate for that.
"There's four different colours - we're actually testing right now to figure out the other two.
"Each player can go through each others' portals in any way. Also, a player can shoot a portal onto their friend's portal and take it over - which kind of comes into play.
"We've also added a way for you to mark up in context in the world, so if I'm playing with you and I want you to put a portal here [points ahead], I can choose it and then you'll see, you know: 'Hey, my buddy wants a portal here.'
"The other thing you can do is if you press TAB [on PC] it will give you a split screen [on your TV], so that you can see what your co-op friend is looking through. A huge amount of co-op experience is about talking: 'Let's try this and this and this' and seeing if it works.
"To be clear, there will be online and split-screen co-op, but I'm talking about a split-screen when I just want to see what you're seeing."
Johnson also gave us an insight into GlaDOS - your female-voiced tormentor, who returns in the second instalment. When asked if you will have a more cordial relationship this time around, he replied:
"Fundamentally GlaDOS wants to have a relationship with you, right? But the only way she knows how to have a relationship with you is to test you. That's about as much as I can give away without killing you."
Check out our Portal 2 gameplay preview here. It's looking very promising, folks.