Look for cooperative games instead of competitive ones. My tweens like Overcooked and Overcooked 2 as cooperative games.

What the title says.

I've heard that playing video games can be good for elderly people wanting to stave off cognitive decline, and multi-player games with family members can add to the connection. As a non-gamer myself, what are some good multi-player virtual games or video games that my nephew (16) can play with his grandpa, my stepdad (83)?