Thanks!
I tested it with two players (referee+player) and five players (referee+four players). But in principle, as it is a rules-lite game, it should work ok with more players. How many people are you thinking of playing it with?
In principle, the rules were designed so that the pacing and end of the game (both tracked by the "tension timer") scale with the number of players in a self-regulated way. Meaning, more players should imply more discarded rolls, and even if the tension timer is larger (as it scales with the number of players), more discarded rolls will move the game toward the turning points and the end of the game more quickly.
Do you want to play it as a one-shot or a short campaign? I’ve done both, so I can help you get a feel for how much time per session it might take for 7-9 players. (With the obvious caveat that it depends on how deep the players and the referee go into each small moment).