It is affectionately and unapologetic-ally a giant monster film. If you don't like critters and robots punching each other, it has little to offer you. On the other hand if you're a fan of Patlabor, Go Nagai, Godzilla/Gamera, or Lovecraft you should be darn happy. It has several tropes or elements of the above present.
Also stay past the credits.
Ron Perlman rawks as usual!