Or, Synth and Punching: The Film.
Marvel have now done a fairly decent range of films across the drama-comedy spectrum, and the majority of them have sat well in their particular niche. Iron Man, Cap America, the team-up films fill out the drama end nicely, and Guardians, Spider-Man and maybe Ant-Man work pretty well as mostly comedies. Thor: Ragnarok tries to be both, and only partly succeeds.
The comic moments are, on the whole, strong. The interactions between Hemsworth and Hiddleston are excellent as ever. They have a wonderful loving/antagonistic chemistry that works well in the context of their brotherly rivalry. Hulk being a bit of a dick is also nice, as we see a bit more depth to his character. "Hulk sad."
But that comedy constantly undercuts the drama they're attempting to build. You're going to spend most of the film thinking "wow, this is sad/important/dramatic, who is going to ruin this moment with a joke?" Spoiler warning, the answer is usually the Kiwi rock monster. I do feel a bit sorry for New Zealand. They've become probably the major source of non-racist funny accent comedy. This goes on from pretty much the very first scene, which is otherwise one of the better openings they've done in a while. The focus on a single character in that sequence was done much better here than in Guardians, which had the rather pointless baby Groot.
Small side note, the first scene has an impressive amount of what I think is my favourite Marvel film sound effect, the THUNG! of Mjolnir.
This search for a joke results in parts of the film feeling unnecessary. Stephen Strange is in the film, as far as I tell for no reason other than to do a fairly weak Sherlock reference. He could and probably should have been cut out entirely. There's also a bit of a thread of under-utilising the actors. This is best exemplified by the presence of Sam Neill and Matt Damon, who are there solely so you go "huh, it's them".
Depressingly this also spreads to Idris Elba, who doesn't really get enough time as Heimdall, and Karl Urban, whose character arc as Skurge is far too shallow for what he can do. Hela has a similar problem, not really getting enough time and seeming to mostly exist for knife fighting scenes. Which is especially annoying in that the action sequences generally felt a bit middling. Technically proficient, but no creativity, and occasionally a bit videogame-y, such as the side-scrolling battle on the Rainbow Bridge, which could have been taken straight from Scott Pilgrim. Though the Thor/Hulk fight was effectively visceral.
The other big disappointment for me is Goldblum as the villainous Grandmaster, who was perhaps not the right casting choice for this. He is probably the best example of the weird comedy-drama conflict. He's positioned as a serious villain, but delivers his lines with the trademark Malcolm vagueness and uncertainty, which doesn't mesh well with the menacing tone he occasionally tries to present. Also a problem with Ruffalo when playing Banner, who appears to be channelling Woody Allen at his most neurotic. More annoying than affecting.
Still, there are a few moments in this that are excellent. They're usually the funny moments, such as Thor's memories of Loki's childhood teasing, or the travel through a mysterious tunnel to meet the Grandmaster (with an excellent musical motif), but there are a few that are dramatic and powerful, such as the ride of the Valkyries. These standout sequences rather outshine the rest of the film.
Honestly, if you're a Marvel fan, you're going to go see it. But it's not one of their best. Probably the major downside of releasing this many films is that some of them have to be worse than others. But wait ten minutes and another three will come along.