Thanks. I was very thorough, so I have no idea what those hidden tasks could be. I'll revisit this after I've played the other games in the jam.
EDIT: Aha! I have to do the tutorial task before starting the game. Now to find the Easter egg.
EDIT 2: I give up. I tried systematically clicking every item in every room and most combinations of items and I couldn't find any Easter egg. Maybe it's a command-prompt only thing, but I was never able to enter any commands that did not have a hyperlink equivalent.