I want to write two reviews of Avengers: Age of Ultron, and they'd both be equally valid. On the one hand, I could say that this year's first blockbuster is absolutely the action-packed thrill ride that comic-book movie fans are hoping for. On the other, I could say it's a mess of overcomplicated storylines and subplots, and that what should have been a gloriously fun superhero romp becomes weighed down by the increasing complexity of the Marvel universe.

Both these things are absolutely true. It's a hugely enjoyable film, full of ingenious action sequences, incredible CGI and sharp dialogue. It's also far too full; scores of plotlines – some resolving threads from previous Marvel movies, others setting up films to come – trip over each other and threaten to undermine the main story. I loved and would recommend it; yet I left the cinema exhausted by its frenetic pace and density of complicated content.

Avengers: Age of Ultron is the 11th entry in the Marvel Cinematic Universe – a series of films which, since the release of Iron Man in 2008, has grown to become the world's biggest and most popular movie franchise. The films (which include Captain America, Hulk, Thor and Guardians of the Galaxy) stand alone, yet they weave together intricately in what is slowly being revealed as an extraordinary piece of forward planning. Characters and plot threads pass between the movies and in Age of Ultron that becomes even more complex.

In some ways, the film feels more like a soap opera than a traditional heroic quest. The ensemble cast includes an extraordinary array of high-profile actors, each playing an interesting, well-developed character with a backstory that haunts them and some sort of redemptive journey ahead. That's a hard trick to pull off in two or three characters, but here writer/director Joss Whedon is trying to do it with more than ten. He manages it too – previous complaints on complexity notwithstanding – and it's an amazing feat of screenwriting that the majority of those threads feel satisfyingly resolved by the end.

The characters manage to remain interesting – even 11 films in (which is good, since there are already at least another ten in development). Iron Man remains morally ambiguous; Captain America stuck in the wrong time; Thor caught between two worlds. The continued disappointment is the absence of strong female characters; only Scarlett Johannson's Black Widow has fulfilled that role so far, with Elizabeth Olsen's Scarlet Witch appearance in this film slightly adjusting the imbalance. The film almost certainly fails the Bechdel test for gender equality, but of course that's a bigger problem which implicates most of Hollywood's high-budget output.

The story itself centres on Ultron, an artificially intelligent robot ostensibly created by Iron Man, who goes rogue and becomes hell-bent on wiping out civilisation. This isn't handled as predictably as one might imagine however, and here's where the film unexpectedly begins to flirt with theology. Thanks to the Internet, Ultron is able to absorb the distilled wisdom and knowledge of human civilisation, and having done so, begins not only to play God, but to see himself as a kind of Deity. Once that happens, he begins to regularly reference Biblical ideas; in planning to purge planet Earth of its inhabitants, he even invokes the story of Noah. It's no coincidence that the culmination of Ultron's plan, and the final battle to stop it, are all situated in a church.

I'm not sure Joss Whedon is making a pointed statement about a destructive Old Testament God, but it's fascinating to see how he's drawn on those ideas to help him create the ultimate power, and threat to modern humanity. Ultron passes judgement on the human race because of its 'sin', and he's certainly not the first movie villain to take that approach. The idea here is that his destructive intent is motivated not by his own sense of evil, but by his sense of human evil; an interesting idea, and not a bad way of illustrating the concept of sin and our need for redemption from a death we deserve.

Alongside this, viewers with a faith may find one of the new characters, enigmatically named 'The Vision', of particular interest. He announces himself into the Marvel Universe with the heavily-loaded words 'I... am', and goes on to fulfil a kind of messianic role in the story; a stark contrast to Ultron's 'fallen angel'.

Still, these are just two ideas among the many competing for our attention, alongside stories of love, bravery, friendship, betrayal and more. Age of Ultron is packed with brilliant, memorable sequences which tell those stories, delivered through a mix of a stellar cast, mind-blowing effects and a truly superb script. The only problem is that there's just too much of all of it. Ultimately it's a film with so many great characters, plot threads and ideas, but because of the sheer volume of content, the whole never manages to transcend the sum of those parts.

Martin Saunders is a Contributing Editor for Christian Today and an author, screenwriter and the Deputy CEO of Youthscape. You can follow him on Twitter: @martinsaunders