So, it is a great map, the Portal and Left 4 Dead crossover is amazing. In fact I went back to do a playthrough of Portal after this and recognized multiple places. HOWEVER, the finale is bugged, if you try the escape option the controls to use the missile turret are broken, without noclip you cannot escape. If you choose fight and win, the special infected are still activate during the ending cutscene, our team was wiped out by a smoker after we had finished and restarted in the saferoom, and due to us having being lifted off the floor in the finale, we were stuck floating and couldn't even get out of the saferoom. We didn't mind all that much as we had already 'finished', but it did put a bit of a sour taste in our mouths. Worth the playthrough, just remember it is a very aged map (no support).
Great, right up until the finale 3rd March 2026