Newton's Cradle
Newtons Cradle is one example that resembles billiards, it represents how billiard balls should interact, but billiard balls also have the friction force from the fabric of the table.
Bumper Cars
Bumper Cars is very similar to pool! Minus the fact that bumper cars have wheels and momentum doesn't matter due to the acceleration of the cars.
Basketball
Basketball is just like the physics of billiards. Instead, they have the force of gravity, the friction when it bounces, and air resistance to worry about.
So I guess less balls helps in this situation.