priya20 reviewed Portal 2

The co-op campaign is the part I'd defend hardest and the part that gets discussed least.

It's a genuinely different design problem — every puzzle has to have a solution that requires two people who cannot occupy the same space, and it has to fail in a way that's legible so you can figure out whose half went wrong. The ping system doing all the communication work is quietly brilliant; you can play the whole thing with someone who doesn't share a language with you.

What holds it at an A is that the solo campaign's back half sags. Once you leave the old Aperture sections, the gel puzzles start solving themselves, and the final act is mostly corridor with dialogue over it. Great dialogue. Still corridor.

The co-op is the better campaign and most people never finished it, which is a shame.