Yeah, the last third was complete rubbish. Guess Dave Cage didn't know what to throw out of the game to make it more cohesive. That AI stuff, intertwined with the temperature drop was completely artificial and rushed. He should have sticked with the Maya dude and make the conclusion there.
Still, overall nice effort. I liked the characters with the exception of Lukas, who was a bit too whiney.
Tyler "bail out" Miles wasn't all that great either, who the hell just leaves when the world is ending!? I'd say the idea was good, but it failed in execution. The quick time events were pretty horrible and the real "story" was straight out of loonyville. I could have taken some supernatural stuff, but that was way too much.