when the graphics are so high tier and non janked that you are immersed in gameplay

A jack off buddy (from 'cum' /'come', meaning 'semen', and 'companion'); a friend that you get together with for sessions of solo or mutual masturbation
Variant of: cumpanion (from 'companion' & 'cum'); jack off buddy & wank bud & JO buddy
Similar to: fuck buddy

Immersive is an improper word that is sometimes incorrectly used in place of immersing.

To describe something which looks/is realistic in videogames