Although already 90% devoted to the multiplayer scene, Valve declared on Geoff Keighley’s “Final Hours of Portal 2” App that the puzzle shooter would be the last of its game not to include a dedicated multiplayer experience beyond simple co-op. The only other game in Valve’s dossier not to feature some multiplayer component is Half-Life.
“Portal 2 will probably be Valve’s last game with an isolated single-player experience. What this all means is something Newell is still trying to figure out,” wrote Keighley, relating a comment made by Valve founder Gabe Newell.
Interesting. I can see co-op being in ep. 3, but I would rather them finish it without that feature, and then make the next installment with the co-op.