I was wondering where the thread for this film was. I really enjoyed it. An effective SF comedy that, like the best SF comedies, works as an SF story in its own right rather than just using SF trappings as the butt of jokes.
Crappy cop-out ending that undercut the emotional threads that drove the film.
Wow, I couldn't disagree more. That ending arose directly from the emotional arc of the film.
It was an allegory for Gary's emotional growth when he finally stopped living as a child (i.e. the elders who'd been sheltering/guiding us finally left us to our own devices). Going out into the world can be turbulent, leaving you without your familiar support structures, and it can be a struggle to build a new life, but the effort can bring you new maturity. Gary clung to the past because he was afraid of facing adult life, and the nicely subversive thing is that he was right to fear it, that it wasn't all hunky-dory to grow up and take responsibility like it'd be in a more simplistic allegory, but facing that hardship still made him a better man.
Besides, in a movie called The World's End, it would've been more of a copout if the world as we know it hadn't ended, don't you think? Gary's goal from the start was to reach The World's End, and he pretty much got what he wanted. So far from a copout, it's a direct payoff to what was set up from the very beginning. And yet at the same time it's a payoff we never saw coming. Which is very, very clever.
(And I really loved the brilliant callback to the "ordering water" discussion -- the way it initially seemed like just a bit of character comedy but then had this awesome symbolism at the end.)