Warning: Contains Spoilers
Plot and relation to the comics
Age of Ultron starts after the other Phase II Marvel Cinematic Universe (MCU) films (Iron Man III, Captain America: Winter Soldiers etc.) where the Avengers are tracking down the last of Hydra's bases after the collapse of S.H.I.E.L.D in Winter Soldier. There they discover that Hydra has been experimenting on humans and two twins (played by Aaron Taylor-Johnson and Elizabeth Olson) have superpowers. After a brief battle the Avengers find Loki's staff (from The Avengers) and after testing Tony Stark a.k.a Iron Man (played once again by Robert Downey Jr.) and Bruce Banner a.k.a the Hulk (played by Mark Ruffalo) find it has an energy source inside which can create artificial intelligence. From this Stark plans to use the staff's ability to create the 'Ultron Program'; an artificial intelligence defense program to safeguard the world from terrors such as Hydra and the Chitauri. However Ultron becomes sentient, rebels against Stark and plots with the twins to destroy the Avengers bringing in a new world order. Initially I was hesitant about the plot as the Age of Ultron storyline, in my own opinion, was one of the best storyarcs in the last five years for Marvel and when they announced that the plot to the film would not resemble this storyline this made me hesitant. However the film's plot was very good considering with thrilling action, quite tense drama and good pacing. The writers managed to put in enough time to help build up the characters personalities but still devoted enough of the film to keep it a thrilling action film. Despite the increased amount of darker scenes compared to other MCU films it still managed to keep the charm and friendly atmosphere at times that characterized other MCU installments. However the film could have benefited much more from more darker scenes. I personally went into the film expecting a darker film compared to the first Avengers but got a relatively light film (although not necessarily a bad thing). The darker parts of the film such as Black Widow (played by Scarlet Johansson) reliving her assassin training and the twins telling Ultron why they hate the Avengers were done very well and one or two more scenes like that would have been good. Of course too many darker moments would have made it too much like Man of Steel or The Dark Knight which would lose the MCU's identity.
The recurring characters of Iron Man, the Hulk, Black Widow, Hawkeye (played by Jeremy Renner), Captain America (played by Chris Evans), Thor (played by Chris Hemsworth) and Nick Fury (played by Samuel L Jackson) are once again done very well. This most likely is due to them playing the characters together multiple times (in the case of Robert Downey Jr this being his sixth time playing Iron Man) so this definitely helped them feel like a team. Each made their character their own and it felt natural they way they spoke where they even had a recurring joke of making fun of Captain America for saying 'mind your language' to Iron Man (a joke my friends unanimously tired of quickly). Also I quite enjoyed the character development for Hawkeye and particularly Black Widow; seeing her dark past allowing us to create a bigger bond with her character. I similarly like her relationship with the Hulk where it is a romantic relationship with Banner but a mother/child relationship with the Hulk. Hopefully in future MCU films, including Infinity War and Civil War, they will continue what they started with this film.
Now the main subject: Ultron.
Then there's the new characters. First off with Vision (played by Paul Bettany) and I liked what they did with him. Having an existing character become the Vision in human form with his characterization that he finally has his own mind and body gave a great alternative to the bleak and self-righteous view that Ultron has. Of course Bettany gave a great performance which allowed it to be more believable and I quite like the joke they had regarding Vision and Mjolnir. I also enjoyed seeing the interaction between Scarlet Witch (Elizabeth Olson) and Quicksilver (Aaron Taylor-Johnson) and am glad that they starred together in Godzilla before Age of Ultron. They seemed to be some form of sibling affection which seemed believable. Especially as we see their evolution from bitter allies of Ultron to loyal allies of the Avengers. However at times the balance between acting with other characters and keeping their generic Eastern European accent made their acting be less believable at times; especially as sometimes the fake accent was a bit off putting at times. Nevertheless quite often both of their acting was done very well, especially with Olson portraying Scarlet Witch as being mentally unbalanced from past traumas, and I hope in future MCU films Olson can improve her acting as Scarlet Witch. Although I was not expecting Quicksilver's fate. I just hope though Olson can use less of a broad fake accent to focus on acting.
First off Stan Lee's cameo. It was highly amusing seeing him in a brief drinking game with Thor while he drunkenly spouts his catchphrase (Excelsior!) for the first time in a live action film. Product placement however wasn't subtle at all and it is a pet peeve of mine. It is slightly distracting seeing Bruce Banner calm down while listening to Beats by Dr Dre, Quicksilver pulling Addidas trainers from Tony Stark's wardrobe and seeing Korean Airlines right next to Ultron's head as he makes a speech. Saying that this again is nitpicking and saying that it is relatively subtle placement compared to other films (Man of Steel and World War Z being prime examples). The after credit scene (which I will not spoil) is a very good hint about the future in regards to the Infinity Gems which will change the MCU indefinitely. My final point is the reference to other heroes. There was one major one and it happens to be one about my favorite Marvel hero: Black Panther. There is a huge reference to Wakanda with Ultron using one of Black Panther's archenemies, Klaw being played by the excellent Andy Serkis, to take Vibranium for upgrades. With Black Panther making his cinematic debut in 2017 I am grateful for the reference.
For great CGI, pacing, acting and character development but for not so subtle product placement, lack of darker scenes and at times the mixed reaction to fake accents (even then I am nitpicking) I would give Avengers: Age of Ultron 8.1/10. I would gladly watch it again and if future MCU films are at this standard we will be in for a treat.