Talk:Portal 2 engine branch

But Portal 2 Engine Branch Base On Alien Swarm Engine Branch Not Left 4 Dead Engine Branch—Unsigned comment added by OdstGamingEternalyt (talk • contribs) Always sign your posts with four tildes (~~~~)

Alien Swarm, and Portal 2, and Left 4 Dead 2 were all forked from Left 4 Dead 1 and worked on concurrently.
— SirYodaJedi (talk) 13:01, 7 July 2025 (PDT)