References to other movies abound - alas, some of them are Roland Emmerich movies - but I did like one touch that not only seems to be tweaking Power Rangers, but Man of Steel too. While cities do get trashed, it is made very clear that the falling buildings are empty, via scenes of mass sheltering after the warning siren, and interior shots of empty offices. It's the abandoned warehouse district redux...not unlike the Spanish Announcers' Table in WWE.
If you're in any way a stickler for science, dear god, abandon all hope now. The battleship-as-baseball-bat is nothing next to the way Gipsy Danger survives an electromagnetic pulse by being "analog," whatever that means in a robot that links two people's brains by computer plug-in (they seem to think it means having your own power generator. It doesn't). Later, the effects of nuclear bombs are, as usual, entirely convenient to the plot.
As for the Kaiju - designs are decent, but they have no personality, and frankly Todd McFarlane would have grounds to sue them all as rip-offs of his Urizen character. So as fun as the giant rasslin' matches are, you are in the end talking about robots piloted by actors with no charisma (that they have it in other movies is irrelevant here), fighting monsters with no real distinctive characteristics. I love movies that build worlds effectively, but the glimpses we get of Kaiju World seem half-assed next to Snyder's Krypton and the future Earths of Oblivion and After Earth.
I also once loved the idea of Guillermo del Toro finally getting a budget he wanted, but now that I've seen it, I'd say he needs to go back down to creatively finding cheap solutions. Like so many other filmmakers who get what they always wanted, it's clear he worked better when people with power sometimes told him "no."