WHO MOURNS FOR ADONAIS?
- Another planetside mission! Another threat to the ship in orbit! The big green hand is an original touch, however. Reminiscent of the cube in Corbomite Manoeuvre in terms of its general weirdness
- The whole "gods are aliens" is not an original concept but well presented in this episode, thanks in no small part to the guest star who really sells the character of Apollo.
- In order to get Uhura to volunteer and carry out the idea of rigging subspace bypass circuit, Spock uses the same reverse psychology that Kirk used on him last week (and in COTEOF)
- Scotty charges Apollo and gets knocked over more times than Lazarus fell off the mountain! And Lazarus was someone who enjoyed falling off mountains A LOT…
Close, but no cigar

That's a "E-6B Flight Computer", most popularly seen in Spock's hands back in
The Naked Time last season.
How do these Tricorders work, anyway? Sometimes Spock scans stuff by pointing the screen side towards its target. Sometimes people point the other side outwards. This episode, both Chekov and Scotty point the bottom of the tricorder outwards.
Maybe these devices are stuffed with sensors and gather data from all directions simultaneously?
A rare instance of TOS technobabble from Mr Spock:
Kirk gets remorseful AFTER he’s engineered the total destruction of Apollo. Again, reminiscent of a Season 1 episode (this time
Map Trap and the buffalo).