- Cross-Dressing Voices: The third Parasite, who is female, is voiced by David Firth. Joe's undead wife is voiced by the game's creator, Remigiusz Michalski.
- Talking to Himself: The second and third Parasites are both voiced by David Firth, of Salad Fingers fame.
- Write What You Know: In case Downfall didn't make this clear, Remigiusz Michalski, the maker of both games, is really well familiar with the world of mental disorders. He's also a nurse (kinda like Susan), and said he had known a person who had suffered from severe depression. There are moments in this game when Susan stands on a bridge and recites very depressing poems in prose - Michalski said that these are the poems that one of his acquaintances (female) has written.
Trivia / The Cat Lady