It just never feels like any genuine effort went into anything other than the visuals. The movie doesn't bother with tension instead just going straight for the money shots (kind of an opposite of Godzilla '14 in that sense), every single character (and there are like 15 to keep track of) is an instantly forgettable stock type yet the movie spends half an hour introducing them and then more time trying to make the audience give a shit about them, John C. Reilly is the only one who looks like he's really having fun, the dialogue is so uninspired that the script actually has the characters joke about it (which doesn't make it any smarter), the soundtrack is just totally random '70s tunes (including inevitably some Bowie and some stuff that was already better used in say Dazed and Confused) playing over scenes for no meaningful reason, there's a bunch of references to Vietnam and visual callbacks to war movies and it all rings completely hollow too. The action is fine, and the monsters look great, but everything around that is just one enormous pile of nothing, and so it robs the action of any stakes as well. To paraphrase Veep, it's a Frankenstein monster if the monster was made entirely of dead parts of other blockbusters.