Maya changes into three consecutive creatures without reverting back to her normal form in between (also demonstrating this ability on "The Metamorph" and "The Taybor"). If she can do this, why didn't she do it in The Rules of Luton (1976), when she was in the form of a bird and trapped in a cage too small for her humanoid form, but not too small for a smaller creature, such as a mouse or an insect, to escape?
Moonbase Alpha is not a military base, so the only personnel that should be titled as "officers" are members of the security team. But Maya is continually referred to as the base's "science officer".
When Alan is fighting the Maya-creature on the Moon's surface, his visor flips up and down as he is thrown over a rock. This of course would have killed him.
When the Maya-creature breaks out of the airlock onto the Moon's surface, it is obvious that the door is made of polystyrene.
As the moon buggy circles Maya, moon dust that is brushed away by the tires exposes the sound stage floor, as well as some kind of material that is ripped up and folded over.
The Psychon male that Maya transforms into in her delirium is supposed to be Mentor, but it is obvious that this is not actor Brian Blessed.
During the fight scene in the Eagle launching area, a sign above the door leading to the Eagle on the launch pad reads "EAGLE FOUR BOARDING TUBE". This is a static sign, but any Eagle can depart any launch pad, so a static sign makes no sense.
The budget for Space: 1999 was supposed to be quite large for the day, but it didn't keep the prop master from reusing props. One such example was the space warp locator from "Space Warp" showing up as an engine tester in The Lambda Factor (1976), as well as a viewing scope inside Koenig's Eagle on Devil's Planet (1977). (Note: Season One's budget was higher than this season's, and Season Two also suffered from the inflation of the mid-to-late '70s, which ran rampant.)
The same lunar surface set is used for both outside the airlock and the Copernicus depression - noticeable by the large rectangular boulder in the center of the set. Not much redressing of the set from one location to the other.
After transforming into the first vicious creature, Maya is seen headed for "the" travel tube. Helena suspects that Maya may be trying to board an Eagle to travel to Psychon, which of course no longer exists. Maya does enter "the" travel tube, then manages to make her way to the Eagles, which has that section of Alpha indiscriminately referred to as the "Launching Area". Not only had Fred Freiberger (who had written this script) succeeded in making the various sections of Alpha smaller for Season Two, he'd attempted to make the base as a whole smaller, making it appear that the base contains only one travel tube, as well as only one Eagle bay and launch pad.
On the Moon's surface, as Alan and Helena are chasing the Maya-creature, the crew and some cast members are reflected in a close-up of Alan's visor.
After Maya changes into Mentor, she changes into the same creature that they encountered earlier in The Beta Cloud (1976) (albeit smaller) - but in that episode, she couldn't transform into that shape because it was a robot and not a living organism.
It is convenient that the data console on an alien ship has data cartridges labeled with Earth based Arabic numerals.
In the second medical center scene, Maya is feverish but still lucid; she knows that the nightmares are taking over and begs Dr. Russell to put her in restraints. If she's that lucid, she should know that restraints meant to hold a normal-strength humanoid wouldn't do a thing to restrain her; she can either transform into a creature strong enough to break them or a creature too small to be held by them.