It will probably work fine
Depends on the group, but around 3 to 5 would probably be my ballpark-number for this game.
The game is free and text only? Is there something in the system that is unclear? If you are new to tabletop RPGs this is very much on the deep-end as it is not even a full game.
Hope this answer helps you.
Thank you for such a nice review!
Hope you enjoy it!
https://jimiskindacool.itch.io/13-thieves