While the monsters reminded me of a plucked turkey with worms, they were created and animated with great care and detail. Very believable movement and behavior from the alien invaders. The joy of this film was watching them skitter through hallways and clamber over humvees.
(Sorry spoilers below)
The space-invader plot is nothing new aside from an added message of how we all need to appreciate America's veterans. And while that's a respectable goal, and I like how time travel can serve as metaphor to help convey a disconnect between a parent and their child, being at odds with what experiences they can share with each other, when the pacing slows it quickly leads to an empty boredom instead of an intended sentiment. The movie did not need to be two hours long and could've benefited from a general condensation.
And then I can't get over the end (more mild spoilers) when, after Chris Pratt's character Dan and his father (JK Simmons) have just ran across the Russian snow-scape and struggled through blinding snow to defeat the last monster, they fall down exhausted, only to have Sam Richardson's character plop right down beside them and share in the relief of it being finally over, although he'd been completely absent from the preceding father-son vs alien showdown (never mind it being unbelievable he could've tracked and caught up to them that quickly)... for a final scene to break my suspension of disbelief, really ends it on the wrong note for me.
The idea of this movie ("veteran awareness day") is worth more than the movie itself.