PG13 means this movie has a lot of destruction, a lot of punching and a few things happening out of sight, but no carnage what so ever. I suppose this is also to appeal to Chinese censorship that wouldn't allow this movie without it.

I've not read any of the comics so I've no idea how faithful this is to the source material, but I know it's rather boring. The humor is pretty good though, it makes a lot better as a straight up comedy rather than any attempt at being carnage or action.

There's also a bunch of things where you might go "Huh? What?" as things just happen in the movie to make the other things be able to happen too.