After a significant build-up consisting of several movies introducing various iconic characters, Marvel finally delivered The Avengers, their big superhero crossover and the most ambitious comic-book movie adaptation at that time.

Directed by Joss Whedon, with an all-star cast portraying the likes of Captain America (Chris Evans), Iron Man (Robert Downey Jr.) and Thor (Chris Hemsworth), plus a long hinted-at plot that gets to the point right away, the film quickly broke a billion dollars at the box-office and it remains one of the most popular movies of all time. Marvel's bold, expensive move paid off, to say the least, and comic-book movies are still just as big as they were back in 2012, some would say more so.

Seeing all these characters together in the same film was certainly a main draw for audiences but without such a talented and dedicated cast, it's arguably unlikely that the film would have spawned as many sequels and spin-offs as it did and led to the continuation of Marvel's (and Disney's) comic-book movie domination. The story sees Loki (Tom Hiddleston) use the Tesseract to open a space portal thereby allowing all sorts of villainous creatures into the world as Nick Fury (Samuel L. Jackson) assembles his team of Avengers to stop him.

Keeping the plot simple was certainly a good move as anything more convoluted than that could have gotten pretty messy. On the other hand, having the film just be about a one-dimensional villain we've already seen in another movie use a macguffin for some vague megalomaniac endgame he doesn't even seem all that devoted to, makes The Avengers feel a little slight depth-wise. Loki himself isn't quite as interesting as he was in Thor but Tom Hiddleston keeps him charming and fun throughout. Most of the enemies the Avengers face, however, are faceless no-name aliens and are only there to be disposed of.

One third of the film is dedicated to introducing characters old and new like Bruce Banner/The Hulk, played by a perfectly cast Mark Ruffalo, the middle part follows Loki's escape and the Avengers having to deal with that, while the finale is just one big New York City-set battle. The film is long but it's paced well with key action beats and, whenever the heroes are interacting with each other, even if they're just standing around discussing exposition, it's a joy.

The Avengers isn't a perfect film. As I mentioned earlier, it isn't exactly a challenging watch, which is both good and not-so-good but altogether understandable. It has quite a few ropey moments, especially near the beginning when Loki shows up to brainwash Hawkeye (Jeremy Renner), or whenever some alien thing we don't know is talking next to a glowing staircase somewhere on a space rock, or when a joke doesn't quite hit the mark. And it's a shame that Loki never gets a final fight against all the Avengers or at least his brother Thor.

Instead, he just basically gives up about halfway through. This is a slick-looking movie with some impressive CG effects (Hulk looks great, mostly) and it's never dull but the cast really is the glue that holds the whole thing together: Robert Downey Jr.'s wit, Chris Evans' earnest heroism, Scarlett Johansson's super-spy antics, all of that comes together beautifully and it effortlessly fleshes out characters you wouldn't necessarily expect to care this much about, let alone at all.

There's no denying what a huge achievement The Avengers was. The fact that Marvel planned out such a ridiculous project so meticulously and it somehow all led to a genuinely solid, entertaining blockbuster is worth celebrating. The film itself is slightly uneven but it's so full of charm and boasts enough cleverly put-together set-pieces that, for any comic-book fan especially, this is simply a treat.

Excelsior!