D
On the bright side, Mystique and Beast were pretty well-played and Fassbender did well despite some awkward lines. Otherwise ...
My main complaint was it was so unrestrained and rushed, from three plot strands in the beginning, an excessive amount of characters and plundering of history (the prologue from the first film was very somberly done, especially in comparison).
Though I'm not very into the comics, the point of the Hellfire Club is that they're not ideological and in any case Shaw turned into too much of a mustache-twirler version of Magneto from the first film.
Xavier and Magneto should have been distinctive, the creators and core of the team, rather than meeting with the former already on a mission for the government. Xavier felt like neither a commander nor a colleague of the others.
Most of the powers were uninteresting-bad guys with powers like Nightcrawler and Storm, a female Angel, the ability to grow gills, Havok with a power similar to Cyclops, Mystique being underused and Emma Frost mostly just looking good (what benefits did the crystal form give her?). Moira looked too similar to Ellen Page's Kitty and acted too much like Jean Grey. They were recruited and then set aside ("We'll have to train, all of us" too much later).
Banshee's flying (gliding?) was pretty bland, as was his, Havok and the villains' personalities.
"Just following orders"-Could Xavier have chosen worse words?
Too much like a remake to be a restart (especially the HQ being attacked and the line-repeating) and too inconsistent to be a prequel (Frost and Stryker being older than in Wolverine, Hank discovering a cure (or thinking he had) early and apparently easily, Xavier knowing the helmet can block his powers).