During the first chase sequence (after Koenig's line "Stay on hard ground"), there is a close-up of someone landing after a short drop. Neither the clothing nor the person's hair matches Koenig's or Maya's.
When Koenig and Maya leave the lake after swimming across their clothes are remarkably dry.
Alien Teleporter reveals human skin beneath its white costume when it lifts an arm.
When Alien Strong is hit by Koenig's bolo, he falls and his human neck skin is revealed beneath his green face mask.
Koenig and Maya had swum across a body of water, yet both of their comlocks are still operational afterward.
During the fight scene where Maya turns into a dog, the handler can clearly be seen holding a leash behind the dog.
The fishing line pulling the alien plant towards Maya (in bird form) can briefly be seen.
When Maya as a falcon flies off with a piece of cloth to soak in water, the bird lands in a muddy field. An immediate close-up has it in the water.
It would've been more logical for Tony to have jettisoned the ship's passenger module before returning to Alpha for Koenig and Maya to use as a base camp. As it was, the pair were left there with no equipment or supplies. They didn't even pack a lunch.
When Maya is imprisoned in her bird form she could have transformed into an insect & escaped between the bars.
Alien Strong doesn't know about Mata's one-hour transformation limit, but he sits down and waits for her to revert inside his makeshift cage.
One of the vegetable judges of Luton accuses Koenig and Maya of cannibalism for eating some of their fellow plants. Cannibalism, however, is defined as one individual of a species consuming all or part of another individual of the same species as food - the inhabitants of Luton are not of the same species as Koenig and Maya.
When Maya, in her bird form, is captured by Alien Strong, Koenig screams that Maya would be crushed if she was to transform back to herself while in the cage. All that would happen would be that Maya would expand out of the cage, she would not be crushed by the mesh wiring.
The aliens were each given one special ability. Apparently "Alien Invisible" was given two abilities, one being able to lift a huge boulder over his head.