The Far Cry endings where you just do nothing in the initial cutscene are fun. Trying to think of more 'hidden shit' like this. Definitely agree, stuff like that is super fun, and while I'm posting HOLY SHIT I MISS CHEAT CODES
in Nier: Automata you can take your brain chip out and just fuckin die. i haven't played it myself, but watching my partner play it it seems that finding all of the weird little hidden endings is a big part of that game.
Reminds me of how you can beat Far Cry 4 in ten minutes by politely waiting for the antagonist to return instead of running off when he leaves to get something