Though it has now been slightly delayed, Phase 4 of the MCU is coming following the epic conclusion of the Infinity Saga. It's wild to think that this massive franchise started over a decade ago with Iron Man and proved this crazy pipedream of a cinematic universe could work.

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Phase 1 was obviously an extremely important era for the MCU. So much of the current success was shaped by those early films, and yet, it was not all perfect. Here are some of the reasons Phase 1 of the MCU is the best era and some reasons it was not.

Best: Something New

Iron Man with his hand outstretched, about to fire from his suit in Iron Man 1

The idea of interconnecting films features Marvel heroes seemed like an ambitious yet unlikely endeavor at the time. But seeing the pieces start to come into place and seeing this vision come to life was a thrill for comic book fans everywhere.

It is still exciting seeing the MCU grow to amazing heights, but there is nothing that has quite matched the excitement of those early days. Each new film would bring a new icon to the big screen all leading up to the heroes sharing the screen together.

Not: Formulaic

Red Skull Tesseract Captain America The First Avenger

The MCU was a big risk, to begin with, and could have been a big disaster. That might explain why they seemed to play it rather safe with their storytelling in Phase 1. After the success of Iron Man, they found a formula that worked for their heroes and stuck to it going forward.

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While it's hard to argue against a working formula, the Phase 1 movies do feel a little rigid and familiar. It was a formula that the MCU had a difficult time breaking for a while.

Best: Smaller Scale Solo Films

Bucky and Steve in Captain America The First Avenger attacking

As fun as the massive team-up movies are, the solo films have always been the backbone of the MCU. These are the movies in which we get to know the heroes, they develop personality and they make us root for them. This was best seen with Phase 1.

The Phase 1 solo films didn't have a bunch of characters and storylines they needed to fit in. They were free to tell their own stories and focus on their characters. There are plenty of great solo films outside of Phase 1, but none feel as self-contained as these early ones.

Not: Creative Differences

Iron Man 2 Jon Favreau Robert Downey Jr behind the scenes

Though the cinematic universe was coming together better than anyone had expected, there were still issues behind the scenes. The biggest issue seemed to be with the directors and the lack of freedom they were given.

Out of all the directors who worked on Phase 1 films, none went on to complete the franchises they started. It seems that those executives that Kevin Feige reported to wanted to focus on the bigger picture, which stifled creative freedoms.

Best: Post-Credit Surprise

Nick Fury comes out of the shadows in Iron Man post-credit scene

It's easy to forget that the notion of a connected Marvel universe was not even hinted at until people saw the post-credit scene of Iron Man. When Nick Fury emerges from the shadows and begins talking about the Avengers Initiative, it changed everything.

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The level of excitement that came from that one scene was phenomenal. It started a fascination with post-credit scenes that add a little extra excitement to the films. Each new scene offers another piece of the puzzle.

Not: Getting Ahead Of Themselves

Nick Fury and Tony Stark in Iron Man 2 in the diner

Once Iron Man became a massive hit and the post-credit scene got fans excited about what's to come, the MCU really took off running. The other films were set up to add more heroes to the roster as they built towards the Avengers film.

However, that excitement may have led to Marvel getting a little carried away with themselves. While Iron Man was a great solo adventure, they turned Iron Man 2 into an overloaded story that spent too much time foreshadowing and setting things up.

Best: The Avengers

The Avengers standing together in battle

As successful as the solo films were, nothing was preparing fans for how exciting it would be to see the Marvel heroes come together for The Avengers. Marvel wisely brought on Joss Whedon to write and direct the film and he delivered a funny, action-packed and entertaining team-up that fans never thought they'd actually see.

Later films have added more and more heroes to great effect, but seeing the team-up pulled off so well when no one thought it could be done is something the MCU might never top.

Not: The Villain Problem

Mickey Rourke Whiplash Iron Man 2

One of the major benefits of Marvel Studios has been that they know their characters better than anyone. They did an amazing job bringing these heroes to life on the big screen and turning them into fully developed characters. However, that was largely at the expense of the villain characters.

RELATED: MCU: 10 Villains We Want To See In Phase 4

It was a well-known criticism of the MCU that their villains often fell flat. Loki was a worthy foe in Thor and The Avengers, but other characters like Red Skull and Abomination were wasted. It took away some of the excitement of those early films.

Best: The Original Six

Marvel heroes

One of the biggest questions about the MCU going forward is how it will cope without some of the heroes who started it all. Though the movies now have such epic heroes as Spider-Man and Captain Marvel, can any of them really replace the MCU's original six Avengers?

From the casting to the character development, these six heroes helped build the MCU into what it has become. Even if the characters weren't household names before, Phase 1 helped them all become icons.

Not: The Incredible Hulk

The Incredible Hulk Smash

With all the successful films in the MCU, there still remains one black sheep. The Incredible Hulk was only the second film for the MCU and it immediately made people second-guess if there's was such a good idea after all.

The movie paled in comparison to the fun of Iron Man while also failing to do anything really interesting with the Hulk character. The fact that one of the first heroes introduced had to be recast is reason enough that the MCU wants us to forget The Incredible Hulk ever happened.

NEXT: The Hulk: 5 Marvel Heroes Who Love Him (& 5 Who Despise Him)