We very much enjoyed this movie. If you are a true fan of Godzilla movies (I used to watch them with my grandfather on Sundays back in the early 70s and have been a fan since), than you will like this one.
I was expecting to see more of each of the Titans but the movie would have to have been 3 hours long. I think it left the door open for additional spinoffs?
Without going into much detail, any movie can be picked apart if you didn't enjoy it. If you like Godzilla, go see the movie, I'm sure you won't be disappointed. If you are not a big Godzilla fan, you may not loose yourself in the fantasy and get bogged down in the minutia.
It's hard to be too critical of a movie about massive giants battling each other. Relax, have some fun and enjoy the movie.