The number of players vary by game but I'd say:
- Ibburim | 3+ players (2+ ghosts & 1 GM)
- House Game | 3+ players (2+ people & 1 HM)
- Cat Game | 3+ players (2+ cats & 1 GM)
- Apartment Game | 2+ players
- Overlay Game | 2+ players
- Masked City of Eido | 1+ player
Some games can easily handle more (like Overlay Game); for most I'd say that whatever the largest D&D or TTRPG of choice party you're comfortable running would work!