WE have had the in-depth superhero backstories and bruising battles with a host of megalomaniac villains.

But our decade-long investment in Marvel’s cinematic universe has always been leading up to this point – and boy was it worth the wait.

Avengers: Infinity War sees all the various factions in the comic book films putting aside their differences (see Captain America: Civil War) and coming together in an end-of-the-world sort of scenario.

The $300million movie also sees 'Earth's mightiest heroes' teaming up with the quirky, rag tag crew of the Guardians of the Galaxy films and there is a joy in seeing key characters meet for the first time.

Everything is at stake in Infinity War with archvillain Thanos (Josh Brolin) on the warpath to collect six 'Infinity Stones' that will grant him unimaginable power.

Yes, it is a bit of an unimaginative premise but what brings it back is directors Anthony and Joe Russo's slick execution.

Thanos justifies his thirst for power with his twisted goal to wipe out half the galaxy's population to 'save' those remaining.

Though it is a CGI character, Brolin voice and motion capture performance is excellent. Only interested in his goal, Thanos comes across as calm, calculating and merciless and has a foreboding presence throughout. But that does not mean there is no time for Marvel's signature snappy dialogue.

Pithy references and in-jokes reward those who have followed the Marvel adventure up until this point and Chris Hemsworth, Chris Pratt, Benedict Cumberbatch and Tom Holland particularly shine as Thor, Star-Lord, Doctor Strange and Spider-Man respectively.

With big ensemble films like this there is the risk it can feel overcrowded but Infinity War overcomes this because there is no baggage – we are already familiar with each character.

And although it clocks in around two and a half hours the pacing is even and excitement rarely wanes thanks to some staggering special effects. The galaxy nervously awaits the conclusion of Infinity War in the second part next year.

RATING: 9/10