It should be called The Fifth and Almost Incomprehensibly Ridiculous Wave.
Aliens hover over earth in what appears to be a very advanced, and probably expensive, spaceship for days, presumably evaluating the situation and planning to extinguish humanity, "because they need the space".
The first four waves, electro magnetic shockwave that disables all utilities and motors, earthquakes, tsunamis, and plague, all seem a plausible and methodical battleplan from the otherworldly intelligence of the intergalactic planetary invaders.
But the fifth wave is more incompetent than any of Wile E. Coyote's plans, and executed even more poorly.
Apparently, the aliens have run out of ways to manipulate physics and now need to take the fight to the ground.
The plan -
Take the form of humans and disguise themselves as military. Convince the adults to send the children ahead to a 'safe zone', in school buses.
Round up the adults. Mass murder them.
Actually transport children to military training facility.
Convince the children that aliens now inhabit other human children's bodies, using new super high tech glasses that make it look like the other children have an alien attached to their brains.
Train the children to be soldiers.
All real aliens, appearing to be ranking military, will man high tech underground bunkers and command the units of fooled children to kill each other until they are all dead.
You can see how the fifth wave doesn't seem as efficient, at least, as the first four.
But even with this idiotic plan, the aliens still could have eliminated mankind and inhabited Earth if one of them had thought to kill all the children while they had them in the buses to the camp.
In the end, the space travelers physics defying trek through the universe and their seemingly unstoppable battleplan, through wave four, were soundly defeated by a 16 year old girl and the captain of get high school football team.
I feel like they got some help from 'the fifth wave'.
The acting was very good.