First things first: Pacific Rim is a movie about 25-storey-tall mechanoids smacking the protoplasm out of genetically engineered, city-destroying monstrosities. It is, therefore, immune to criticism on at least one level. If that’s your kind of thing, you should probably go watch it in the cinema. If it isn’t, you shouldn’t. That said, there’s a difference between criticism and critique.
This isn’t going to be a review, more a pondering of some points of design and storytelling. However, there will be spoilers, so it’s all below the cut.