this is a classification of genres that don’t fit individually but fit very well inside the genres in game:
Action: Platformer, First-person shooter, Third-person Shooter, Fighting
Adventure: Story-based, Survival, Open world (from reaserch), Espionage
RPG: Tactical, Action
Strategy: 4X, Turn-based, Real Time, Tower Defense
Simulation: General, Management, Racing
Casual: Time-Killer, Family, Party, Education, Arcade
these sub-genres can pair with others and create combos like Open worlds real time strategy tho some of these is kind of stupid to be combo’ed to others like party and racing, those will be more dependent on the develop process to compensate the lost multi genre bonus, but not between sub-genres in the same genre.