There's a fair amount of mess in X-Men: Days of Future Past, but it’s often good mess. It’s also intentional mess because it’s a time travel picture. If you remember any of the previous X-Men movies, lots doesn't make any sense. But it also doesn't matter–director Singer and screenwriter Simon Kinberg rely heavily on a viewer's shaky memory of the franchise.
Future has a good pace and some good sequences. Not a lot of them, unfortunately; the big finale is a disappointment, for example, with Singer trying to emphasize a personal story there. Only that personal story hasn't really been important to the rest of the movie because it's all been about the end of the world.
All of the stuff in the apocalyptic future is goofy. There's a lot of murky CG and unmemorable supporting cast in busy fight scenes. Ian McKellen and Patrick Stewart look somewhat lost in the confusion.
The acting quality varies. Hugh Jackman has fun, before the script demotes him. James McAvoy and Nicholas Hoult are both good. Evan Peters gets the best sequence, Michael Fassbender gets the worst. Fassbender gets the shortchanged throughout the picture. While he’s really underused, he does get a couple excellent scenes. Big villain Peter Dinklage is awesome. Jennifer Lawrence is mediocre. Everyone in the future except Elliot Page is bad. Like I said, it's just too goofy.
Good photography from Newton Thomas Sigel, bad music from John Ottman.
Though any ambition beyond franchise revitalization is disingenuous, the film definitely entertains. Sometimes distinctively.