Progression is a strange thing because although in theory it's good, in practice it can be less than that. The first Fall film was a great indie (-feeling?) movie set almost entirely in one location with a limited cast. With such little they managed to portray a sense of vertigo and dread and it all just worked.
Fall 2 takes things further, and not just in setting, ambition or cast. It adds a story, providing thrills on an axis orthogonal (but not replacing) to that of the original. And while the plot on its own is pretty good, and the fearmongering on its own pretty good, these thrills get in the way of each other in a way that kind of diminishes both. And that's a bit of a shame.
Add to that the presence of one of the most dislikable protagonists in a film in recent times and you have a film that, although does it's job, doesn't quite make a recommendation. But hey, judging by the stinger at least we have a developing Fall Universe to look forward to.
