The "it's green" gag
from this episode would later be used in the
"Star Trek: The Next
"Relics" where Scotty asks Data about a bottle
of whiskey to which Data replies "it is green".
When Rojan reduces
Chekov, the helm/navigation console is facing the engineering
station, not the main viewscreen as it should.
The Kelvans come from
the Andromeda galaxy. Gene Roddenberry had written a format for a
television series in 1976 called "Andromeda", which eventually
became a series in 2000 entitled "Gene Roddenberry's Andromeda."
In the wide shots of
Kirk and Rojan fighting, the faces of the stunt doubles can be seen.
Kirk moves his eyes and Uhura blinks when they're
paralyzed, despite the fact that Rojan neutralizes "nerve impulses
to the voluntary muscles."
When Scotty gets drunk and tosses an empty bottle
away, there's a dubbed in sound of glass breaking, but when he
collapses, the bottle is unbroken at his feet