This looks great! Released under creative commons (so free to use, remix and republish) it has very simple mechanics and relies on 'theatre of the mind', which is appropriate given 'John' is having a 'neuro-spicey' day. I don't have any friends to play with, but that's ok, i'll just play with the voices in my head.

Everyone is John is a humorous, competitive roleplaying game about playing the various personalities of John, an insane man from Minneapolis. One participant is the GM, or, in Everyone is John lingo, “Everyone Else.” All of the other players are Voices in John’s head.

Everyone is John uses six-sided dice (you really only need one, but it might be easiest if every participant carries one) for play.

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Everyone is John

A competitive roleplaying game for three or more people.

John

John is a totally insane man in Minneapolis. He is controlled by the Voices in his head — one at a time, of course.

John is not terribly competent; he has difficulty with a lot of things that you and I might take for granted. Whenever John attempts anything that an ordinary person might have any chance of failure at, he needs to roll for success.

The Voice who is currently in control of John does the rolling. If that Voice has a skill that covers the challenge, the Voice needs to roll a 3 or higher on the single d6. If it doesn’t have a skill, it needs to roll a 6. However, before the roll, the Voice can spend any number of Willpower points to get a +1 per point spent on the die roll. This can make success automatic.

Becoming the active Voice is a bit of a challenge, though. Whenever John wakes up or gets hurt, a test for control of John happens. Also, whenever the currently active Voice fails a roll or completes its obsession, a test for control of John happens.

When a test for control of John occurs, all of the Voices who are interested simultaneously bid one or more Willpower points (if you’re using tokens for Willpower, it’s easiest for everyone to just hold out the tokens in their closed hands, and then, when everyone’s ready, reveal the number of tokens). Voices don’t have to bid if they don’t want to (and you can hold out zero tokens if you want to fake out the other Voices). The highest number of Willpower becomes the active Voice. If multiple people bid the same highest amount, then they roll off to see who becomes active.

Get the full rules here: https://rtwolf.github.io/Everyone-is-John/