

I finished Portal 2 co-op mode a fair while ago (and the bonus levels that I honestly could have missed entirely, because it’s not really indicated that they exist) and started the single-player mode. It’s fine, and I’m interested to find out the details (although it’s hinted at enough that I think I can guess), but I actually feel the single-player mode is a bit too long. You’re moving through the levels, but I none of them have been that challenging and in the later game (assuming I’m near the end), a lot are just too straightforward. Possibly I was spoiled by the co-op mode and I would have liked the single-player mode more if I’d done it first.
I’d say so, yes. Coordinating two players to do their things in the right order and getting the timing right requires a lot more thought. I did finish the single-player mode and there was one near the end that had me thinking for a bit, but there was nothing as challenging as what’s in the co-op mode.