Long Before Friendslop, Portal 2 Made Co-Op Cool

April 18, 2026 marks the 15-year anniversary of Portal 2's release.

Below, we reminisce about its memorable story, novel cooperative two-player mode, and enduring comedy.

There was a time in the PlayStation 3/Xbox 360 era when Valve was spoiling us with games, packaging some excellent titles in The Orange Box and bringing us back-to-back Left 4 Dead entries.

But the company hit a stride with the 2011 release of Portal 2, which might be its finest accomplishment of that generation.

Following up from 2007's Portal, Valve would still have had a hit if it had only made and released the single-player campaign, but the developers went the extra mile with the addition of a full-fledged co-op campaign--which itself would have been an equally worthy sequel to Portal on its own, and in retrospect, was a harbinger for cooperative and social games trending today.