Painful.

Rating: 4/10 (4 May 2018)

This is a tonally confused conclusion to a tonally confused trilogy. Despite enjoying his role in The Avengers, I never liked the Thor standalone films. Knowing that, I approached this one with a degree of the cynicism I wish I'd had walking into the other two. In this regard, I'm amazed that I managed to be let down anyway.
Like Iron Man 3 or, indeed, the first Thor movie, the story is entirely secondary to how many jokes they can make. This worked for The Guardians of the Galaxy or Fox's Deadpool, but they had the advantage of making up for thin, predictable plots with being funny (even after multiple viewings). But, in this case, the ongoing attempt at humour is largely restricted to "Expectation vs. Reality" sight gags or acts of out-of-character incompetence and buffoonery that ruin the tension and lessen the stakes. In effect, the film deflates itself and it's epic mythological roots in favour of "safely" playing off the events of the Norse endtimes as a comedy for small children.
Despite a slew of respected veteran actors, many of the cast seem to be either reading the script off of a teleprompter in real-time for the camera or have been asked to self-deprecatingly improvise in favour of any of the three screenwriters to actually finish a scene. Hemsworth, Hiddleston and Ruffalo are all at total lowpoints for their Marvel characterizations thus far, more seeming to be personally goofing off on the occasion that I believe a word they're saying. Again, the pervasive levity renders it impossible to take anything seriously.
The only reason that this is getting so generous a score is that the visual effects were entirely adequate. Not good, adequate. At it's best, this film is functional. But, on average, it's a choppy mess with mediocre acting from people who desperately deserve a much better script. If you feel the need to not miss any possible reference points in Infinity War, then you could waste your time on something worse, but a technically inferior picture would probably prove more entertaining in a perverse way. It's no weaker than it's titular predecessors, but that means little in the way of enjoyability.