Spoilers. So if you don’t want to know what happens, don’t read further.
General opinion: meh. Didn’t suck, wasn’t great. Kinda-sorta was like the original, except that the aliens are substantially more malevolent and substantially less imaginitive. Whereas in the original they come to Earth to deliver the message “Stop being aggressive or we will murder the lot of you,” this time they come bearing the message “Stop destroying the environment or we will scrape the Earth clean of all forms of life and start it over with the small menagerie of critters we’ve picked up.” They’re still assholes, just dumber.
Gort again plays a role, but instead of being a 9-foot-tall robot, it’s a 30-ish foot tall collection of hungry nanites in the shape of a robot. Gort becomes the cloud of nasties that you see consuming every damned thing in the commercials. The reason why the aliens are all pissy is because the universe has very few planets capable of supporting complex life, and humans are somehow or other killing this one (it’s never explained exactly how, but somehow Everyone Just Knows that humans are killing the Earth). Thus the aliens are here to wipe out humanity in order to save the Earth. But rather than doing something vaguely sensible like releasing an engineered plague to wipe out humans… the Gort-cloud will eat *everything* down to bedrock, and then they’ll reseed the place.
The aliens in TDTEST suffer from a common failing of Hollywood aliens: they have all kinds of advanced tech and power available to ’em, but almost no creativity whatsofriggenever. If you have the sort of abilities displayed here, you don’t wipe out the Earth. Instead, you terraform Mars and Venus and seed *them* with life. Sow self-sustaining colonies throughout the solar system up to and including the Kuiper Belt. But I guess that’s not as dramatic as a Message Movie.
In the end Klaatu (a properly cast keanu Reeves… all he has to do is stand around like a statue, which is well within Keanu’s range) decides to call off the Gort-cloud after it has eaten everything from Indiana to Maryland to Vermont… the same general area that got smacked down by Angry Trees in “The Happening.” The oft-used conceit of the alien seeing humans emote and deciding that they’re not so bad after all is employed once again.
But while the original version of TDTEST had Klaatu shut down all transportation and electrical systems for a temporary display of power near the end of the movie, in this version, he has the planetary technological infrastructure shut down right at the end, leaving humanity in a state of imminent collapse. The tech shutdown is presumed to be a permanent feature, rather than a temporary display. The purpose was to give mankind a chance to change it’s destructive ways. But what such a thing would really do is not only cause famine, plague death and mayhem on a level never before imagined outside of “Zombie Apocolypse” fiction, but also lead to the virtually complete destruction of the ecosystem. Six billion starving, freezing humans, devoid of basic machinery, will not only chop each other into rump roast, they’ll kill everything that flies, crawls, walks or swims, and burn anything even remotely flamable to stay warm. If humanity can get the technology up and running again (and one would of course certainly expect this to happen… I mean, how the hell do you permanently shut down even the concept of a diesel engine?), it’s hard to predict the future, but one thing would be certain: we’d harbor a genocial grudge against them alien mofo’s what who killed nigh on five and a half billion of us. If the aliens make the mistake of not regularly checking up on us, the next time we meet there’d be a hell of a fight.