kill 1 of every npc (including penguin and monkey) idk if you should complete the game after or not.

Good idea. All three Bowsers should be killed, I'd say. I think it's also important to set ground rules. For example, should it be mandatory to collect the coins of the enemies that you kill? If not, are pacifist kills (such as an enemy walking off a cliff) count?

if the penguin and monkey count, then the coin shouldn't be necessary and pacifist kills should count, right?

We already have all enemies

yea all enemies exists, but the new idea is only 1 of each (just in case that's https://www.speedrun.com/sm64ce?h=All_Enemies&x=q25wpj82 )