Flo Lieb’s review published on Letterboxd :
This movie is a narrative mess where hardly anything makes sense and exists solely to set up the next joke.
Ragnarok is upon Asgard but it never feels like it since the plot makes no effort to explain its relevance. The exiled Odin dies, because... this is not explained. With his death Hela returns to Asgard to rule over the galaxy – I assume? Get in line, lady, Thanos called dips on that. Thor and Loki are stranded on another planet and then return to Asgard to face Hela and stop Ragnarok. That is the plot but the movie is more interested in stuff that has nothing to do with it and could easily have been cut entirely.
Starting with Dr. Strange who essentially just pops up here to connect this Marvel movie to the grander scheme of MCU. He "captures" Loki and lures Thor into his mansion to talk to him. He could've just approached him for a talk but then Waititi would've lost a comedic moment. More present in the film but just as useless is Hulk. There is no explanation given how Hulk showed up on Sakaar. Presumably he flew his jet from Age of Ultron from Earth into Outer Space, crossed our solar system to accidentally get trapped in a wormhole.
Hulk's role in the movie is comic relief – which seems kind of weird since every character's role in this movie is comic relief. Hulk is not really necessary to further Thor's cause. Sure, it's neat to have a Hulk fight alongside you but ultimately if the "strongest Avenger" wasn't there the mission wouldn't really falter. As a result the Planet Hulk storyline is kinda lost in this movie. Waititi – giving a Sharlto Copley impression – voices Korg, a gladiator who tries to start a revolution. This revolution is the narrative counterpart of Ragnarok. Someone mentions it but the movie doesn't give a shit about it. A revolution for what? For the people of Sakaar? For the dozen "prisoners with jobs"? It is never made clear and outside of Hulk fighting in an arena this is as far as the Planet Hulk storyline goes.
As a matter of fact, considering the whole Asgard subplot and loyalty approach for characters like Loki und Valkyre, it would've made more sense if the film had replaced Hulk with Beta Ray Bill for Thor to fight on Sakaar. And to try to get Beta Ray Bill to help him (Thor) prevent Ragnarok und save Asgard from Hela/Surtur. As far as comic relief goes this would've worked just as well. With Thor and Beta Ray Bill sizing each other up, both claiming they're stronger than the other, etc.
The action is hardly inspired, the humor is everywhere. Less is more, even with humor and especially if the director gives himself a supporting role as a constant quip machine. I enjoyed Mark Mothersbaugh's score though (the movie could've utilized it more) and I liked the font (design) of the title card. It is an entertaining movie, not necessarily better than the original Thor but as third outings go it is not worse than Iron Man 3 and better than Captain America: Civil War.