I ran the game in play test most commonly with 5 or 3. I personally think the game works best with 4 or 5 given the pressure cooker nature of the game. I think a 3 player game would be better for a more social type of game. I will note I tried it at 6 once…it should be avoided, it was just a mess with too many moving parts and its hard to keep 6 in a similar time sync.

There are 7 other settings in the first expansion book, the draft text is in this backer only update if you didn’t back it let me know and I’ll flip the content your way.
kickstarter.com – Update 29: SETTING BOOK DRAFT & SHIPPING NEWS · Headspace RPG