The ambitious animated Marvel series 'What If…?' has reached its conclusion. The good news is that if you enjoyed the nine episodes of the show, there's another season on the way.

The series features a whole bunch of fan favourite characters, including Peggy Carter, T’Challa, Doctor Strange, Killmonger, Thor and more.

It imagines alternative paths for the characters in a "multiverse of unlimited possibilities."

Observing all the goings on of the multiverse is the Watcher, voiced by Jeffrey Wright, who is sworn to never interfere with what happens in each universe.

That is, until the series finale, in which he must get involved, or the multiverse could fall apart.

There were some really fascinating concepts as different journeys were imagined for various Marvel characters. And plenty of fan service for followers of the MCU.

Here's how we'd rate all nine episodes of the series.

9. "What If… Thor Were an Only Child?"

This seventh episode of the series was really banking on the comedic range of Chris Hemsworth. And don't get us wrong, Hemsworth is definitely able to deliver on comedy. It just didn't translate as effectively to animation. There were some nice ideas in the episode, such as how Jane Foster (who, uncharacteristically, is turned into something of a party animal by Thor) and the God of Thunder were always meant for romance; plus the friendship between Loki, now embracing his Frost Giants roots, and Thor was sweet. But the whole finale of finale of Thor's mother Frigga arriving to tell her son off was silly.

8. "What If… Captain Carter Were the First Avenger?"

A strong debut episode for the series, yes, and we all know Peggy Carter does not get the adoration she deserves. There were also some pretty great action sequences, and the flirting between Peggy and Steve was touching. Still, the episode was essentially a remake of 'Captain America: The First Avenger' with Peggy becoming Captain America instead of Steve. The episodes to follow were simply more ambitious.

7. "What If… the World Lost Its Mightiest Heroes?"

Nick Fury had an idea: to bring together a group of of remarkable people, to fight the battles others never could. But what if every person Fury hand picked for the mission was assassinated by a mysterious force. Would the Avengers Initiative ever come to be? This third episode of the Marvel series answered "Yes, it still could." After all there's a plethora of MCU characters to draw from. The episode took unexpected twists and turns, with highlights including a nod to the Edward Norton starrer 'The Incredible Hulk' and Loki being his sneaky self, taking advantage and conquering Earth. It was generally quite a downer of an episode though, seeing Tony, Thor, Natasha and Banner killed off.

6. "What If… the Watcher Broke His Oath?"

The final episode of the series did an effective job of wrapping things up as well as having viewers reflect on the events of the series overall. In order to save the multiverse, the Watcher takes a chapter out of Nick Fury's book and assembles a team, taking individuals from different universes. Captain Carter, Killmonger, Gomora, Star-Lord T'Challa, Strange Supreme and Party Thor thus band together to take down Ultron. And a couple of other familiar faces pop up too... There's some good banter between the teammates and a gripping battle, though the episode did feel a bit rushed (having to stick to that 35 min running length). Plus there wasn't too much material left to make a season 2 highly anticipatory. Still, it was a satisfying finale.

5. "What If… Killmonger Rescued Tony Stark?"

In a way, this episode asked two questions. There's the titular question regarding Killmonger saving Tony Stark; but its second question is What if Stark never became Iron Man? What results is a naive and far too trusting Tony putting all his eggs in one basket and giving it all to the power-hungry and deceptive 'Black Panther' antagonist. Killmonger not only ends up killing Klaue, T'Challa and Rhodey in his determination for revenge - he also takes out Tony himself. It doesn't stop there either. Killmonger, as cunning and manipulative as he is ruthless, manages to set up a battle in Wakanda, then aligns himself with the locals and saves the day, leading to him being crowned the new Black Panther. A gripping cliffhanger ends the impressive episode as Shuri and Pepper Potts agree to join forces to take down Killmonger.

4. "What If… T'Challa Became a Star-Lord?"

By far the most humourous episode of 'What If...', the second episode of the Marvel series imagines that the Ravagers picked up T'Challa instead of Peter Quill. It was emotional hearing the late Chadwick Boseman return to his most renowned role. It was also very funny, as well as fascinating, to see how much cooler T'Challa would have been as Star Lord. He's got the whole galaxy fan girling him (one highlight beinf Drax asking for a selfie), Thanos at his service, and a very pretty Nebula flirting with him. The episode concludes with a rip-roaring heist which is a welcome departure from the standard MCU stuff. All in all, a highly enjoyable standalone episode.

3. "What If… Doctor Strange Lost His Heart Instead of His Hands?"

This fourth episode of 'What If...' went very dark - but in a good way. A car crash leads to Dr. Strange losing his girlfriend Christine Palmer, rather the hands he needs for surgery. Strange keeps attempting to reverse time and save her, but no matter what action he takes, she ends up dying. It's a brutal and heart-breaking montage. Strange thus decides to train up at the Lost Library of Cagliostro so he can develop his powers and bring Christine back to life. However this decision leads to the development of two versions of Strange in the one universe. Christine, now brought back to life, is repulsed by and rejects "Strange Supreme", who kills and absorbs the other Strange, and the universe is destroyed, despite Strange's plea to the Watcher to save it. The episode reflects on how hazy the line between good and evil can be. It also serves as an effective reminder of just how powerful Strange is, and one is excited to see him turn up in the next Spidey movie, and his later solo sequel 'Multiverse of Madness'.

2. "What If… Ultron Won?"

This episode was basically 'Infinity War', which most Marvel fans will admit was probably a better movie than 'Endgame'. It makes sense then that this penultimate episode of 'What If...' ranks higher than the final one. It imagines that Ultron got what it want, obtaining the Mind Stone as well as Vision's body, and defeated the Avengers, with only Clint and Natasha surviving. Now, with most of humanity being wiped out, they're alone in their conquest to defeat Thanos. And we're reminded that for all the shtick fans gives them as the weakest Avengers, they can be pretty badass. It's a tender reflection on how powerful the pair's friendship is and a bittersweet moment comes when, in a reverse of what happened in 'Infinity War', Clint sacrifices himself so Natasha can live. His fall into a pit of drones, shooting an explosive arrow towards them in slo mo, could be the most affecting image from the whole series.

1. "What If… Zombies?!"

Ok, the zombies episode of 'What If...' has to be its best based on its ambition, fan catering, and all-out lunacy. I mean, you've the talking head of Paul Rudd, aka Ant-Man, suddenly appearing, the most random team-up ever between Bruce Banner, Hope van Dyne, Peter Parker, the Cloak of Levitation, Bucky, Okoye, Carter, Happy Hogan, and Kurt; and oh, there's the fact that the Avengers are all zombies now (some brilliant animation here). Oh yeah, and then there's Vision who, in a nod to the romance of 'Wandavision', has been keeping his zombie girlfriend alive - by feeding her bits of T'Challa. The episode ends with zombie Thanos showing up (a Thanos moment only surpassed by him showing up in the Ultron episode, and being immediately cut in half). Aside from being nuts, the episode was jam-packed with action and surprisingly emotional, so it more than deserves to come out on top.

Watch all nine episodes of 'What If...?' are on Disney+ now.