In short: an overwhelming ungodly mess.
I was so hoping to fall head over heels with this film. Alas, twas not meant to be. Pacing (or should I say the abysmal lack of) just kills this film. As Jelly said in his review, this thing is breakneck from frame one and there's literally only one brief pause before we're being shoved into another set piece. The human element is a trainwreck. A cabal of high profile/award-winning actors doesn't mean jack when they're given nothing but garbage lines to deliver and no sense of emotional centering; they're just mostly caught up in the whirlpool and sucked along. Dance is completely wasted; an utter shame. Everyone else coughs up idiotic verbiage that might've been cute in a 1950's B-flick, but is downright cringe-worthy nowadays. We CAN do better, and should have. By comparison, the plot and script of K vs. KG in 1991 is the zenith of G-films. The "humor" in this, in fact the entire script, feels like it was written by a collective of 6th graders who downed a case of Monster and Red Bull and referenced a stack of well-thumbed MAD magazines. And I'll grant you that Mike Dougherty appears to truly be a hardcore kaiju fan, but his direction leaves oh so much to be desired. He's about as subtle as a sledgehammer blow to the face. The soundmix? An overpowering typhoon of loudness. I literally had a headache when the movie was over from the assault on my eardrums. The bits of the classic Toho scores were almost imperceptible; buried alive under an audio avalanche of pounding music with no narrative, and the sound F/X design felt like the technicians found every single explosion, thunderclap and earthquake noise they could lay their hands on and just layered them one atop another atop another until it all just blended together in excessive painful wall of doomy-gloomy noise.
Effects were a mostly impressive bag, This film;s only saving grace in fact, but it was hard to tell thanks to all the CGI rain and murkiness hiding most everything. I'm sorry, but I am absolutely fed up with night time & rain laid over the top of hero/monster scenes. There's just no excuse anymore! K:SI proved that daylight battles with fully CGI creatures is doable and, for the most part, practical. The sludgy darkness in this flick is a HUGE step BACKWARDS. Costs too much and takes longer to render accurately??? Fine. I'd rather have only two setpiece fights in broad daylight than an half dozen in near total darkness and/or pouring rain. *SIGH* Also not caring for a Godzilla so stump-necked that his head is practically coming directly out of his shoulders now. Ugh. Ghidorah's heads were too rubbery/undulating in the film. But I did like the extra layer of believable body and wing/flight movement; he's not the stiff wire-flown beast of days past and that at least is a good thing. Mothra and Rodan too under-used, given the implication in the various trailers that they'd be equal time-sharers with the other two guys. Mothra was the biggest waste; she was literally a deus ex machina, and a poorly explained one at that. Rodan got some real love finally; he had probably the best entrance and a terrific display of powers. Best portrayal of the big red bird since his '57 debut.
If next year's G vs K turns out to be on the same level as this then I think I'll skip theater showings and wait for home video for any further MonsterVerse entries after 2020. Man, I am bummed. I was so looking forward to this. Perhaps it was too much of a build-up and five years of waiting & wanting. I am torn about more of the same as well. I want this to succeed because I want more Godzilla, but if everything from here on in is more of this then I'd just as soon it revert back to Toho. Honestly, I don't feel that G:KotM deserves a big BO. As always, IMHO, YMMV, etc.