Thor Ragnarok Reviews: 12 Early Reactions You Need To See
5. Great Action
Though a couple of reactions have mentioned Ragnarok being "slight" (which probably refers to length rather than story and ideas), the trailers have sold the idea of huge scale and a major threat (not just to Asgard but to the entire universe) with visions of Thor's homeland being destroyed and Hela eassily beating Thor in combat (as well as needing multiple Valkyrie to fight her in a flashback).
So the idea of there not being lots of action was never going to fly.
Luckily, it seems there's more than enough in there, and it's all done very well, according to at least a couple of the early reviewers. This is very much new territory for Waititi, so if there was one area he might come up short, it could have been here. Kudos to him for managing to pull it off, by the sound of it.