Directors Joe and Anthony Russo were given a nightmarish task - to shoot two of the biggest blockbusters of all time back-to-back, whilst making sure they would live up to expectations.
Forced to juggle a variety of set-pieces, story-lines, studio notes, and movie stars, the duo were constantly under pressure.
Although an enjoyable superhero romp, Avengers: Infinity War showed signs of overcrowding and fatigue.
Fortunately, Avengers: Endgame is an exhilarating, intellectually satisfying, and emotionally-resonant experience.
Picking up where Infinity War left off, the world is struggling to come to terms with several new developments.
Thanks to 'The Snap', the Mad Titan Thanos (Josh Brolin) completed his goal of erasing 50 per cent of all life in the universe.
The remaining Avengers - Tony Stark/Iron Man (Robert Downey jr.), Steve Rogers/Captain America (Chris Evans), James Rhodes/War Machine (Don Cheadle), Natasha Romanoff/Black Widow (Scarlett Johansson), Bruce Banner/the Incredible Hulk (Mark Ruffalo), Thor (Chris Hemsworth), Clint Barton/Hawkeye (Jeremy Renner), Nebula (Karen Gillan), Scott Lang/Ant-Man (Paul Rudd), and Rocket Racoon (voiced by Bradley Cooper) - eventually hatch a plan to bring everyone back.
With its exhaustive three-hour run-time and its collection of references to previous movies, Avengers: Endgame is the ultimate love letter to fans of the 22 Marvel Cinematic Universe instalments.
In tone, content, and style, all three acts are completely different to one another.
This instalment gracefully transitions from brooding drama, to fun time travel adventure, to zany heist flick, before the third act/climactic final battle cranks it up to 11.
The Russos, Marvel Studios head-honcho Kevin Feige, and screenwriters Christopher Markus and Stephen McFeely understand the importance of creating well-rounded, meaningful characters.
At the centre of the intricate plot-threads, CGI vistas, and explosive action sequences, our main characters all get a chance to shine.
Evans, once again, brings a mix of charm, optimism, and sympathy to everyone's favourite red, white, and blue super-soldier.
Uncovering new layers, Downey jr. makes sure to flesh out Tony Stark and Iron Man.
Characters like Hawkeye, Black Window, Ant-Man, Rocket Raccoon, and Nebula are given more character development this time around.
With Hulk and Thor finding new obstacles to overcome, Ruffalo and Hemsworth excel in many of the movie's best scenes.
The movie's twists and turns, massive set-pieces, and heart-breaking final moments are all incredible.
However, Avengers: Endgame is made whole by its quieter moments.