itch.io

Games that try to simulate real-world activities (like driving vehicles or living the life of someone else) with as much realism as possible. Simulators generally require more study and orientation than arcade games, and the best simulators are also educational.

A game in which the player is not constrained to achieving specific goals and has a large degree of freedom to explore, interact with, or modify the game environment 

Games where the primary goal is keeping the player character alive under harsh circumstances such as dwindling resources or a hostile environment.