These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Moe Moe: In one episode, Lunar-papa, Gozaburo, and Masa (ordered to) crossdress as schoolgirls and catgirls and act out moe stereotypes in an attempt to understand a girl's heart. It really is that horrible. Ends with Sun suddenly receiving cat ears, which everyone agrees is incredibly moe (before being blasted away).
Nightmare Fuel: The second half of the 2nd OVA, which does a Genre Shift from comedy/action to straight horror, borrowing elements from The Ring. Saturn will probably haunt your nightmares now.