The early reviews of X-Men: Days of Future Past were potentially damaging. There was talk of the narrative being far too complex for the average movie fan to enjoy and many were suggesting Bryan Singer had bitten off more than he could chew by having the beloved characters from the original X-Men trilogy joining forces with their younger selves. 

X Men Days of Future PastJames McAvoy [L] and Patrick Stewart [R]

Starring Sir Ian McKellen, Hugh Jackman and Patrick Stewart alongside Jennifer Lawrence, Michael Fassbender and James McAvoy, X-Men: Days of Future Past is certainly a hotbed of serious acting talent, but very often, big names simply aren't enough to carry a poor script. Luckily, for 20th Century Fox, writers John Byrne, Simon Kinberg, Matthew Vaughn and Jane Goldman haven't written a poor script. They haven't even written an overly complex script.

More: Simon Kinberg says X-Men: Apocalyse will be even bigger than Days of Future Past

"The most ambitious and ingenious of the long-running series, X-Men: Days of Future Past keeps the key crew of mutants busier than ever," said Claudia Puig of USA Today.

"[It's got] a lot of plot. And yet, despite resulting in a film that brings together the cast of the original X-Men films and the upstarts of the clever 2011 reboot X-Men: First Class, Singer keeps what matters clear and snappy enough," wrote Christopher Borrelli of the Chicago Tribune.

X-Men Days of Future PastNicholas Hoult [L], James McAvoy [Center] and Hugh Jackman [R] in 'X-Men: Days of Future Past'

"Singer's return in the pretzel-logic pop fantasia X-Men: Days of Future Past is so triumphant because of how effortless he makes connecting the dots seem. It's an epic that couldn't be more Byzantine on paper but scans with ease on screen," said Chris Nashawaty of Entertainment Weekly.

"It all trots along at a brisk pace with genuinely impressive special effects and decent gags. Bryan Singer really cares about his mutant outcasts, weaving just enough drama into the superhero shenanigans," said Cath Clarke of Time Out.

""X-Men: Days of Future Past'' blows a breath of fresh air through the musty Marvel universe, which increasingly is all about pandering to hard-core fans rather than trying to make good movies for everybody," said Lou Lumenick of the New York Post.

X-Men: Days of Future Past hits theaters in the U.S from today (May 22, 2014). 

More: Watch the trailer for 'X-Men: Days of Future Past' now