The extent to which a game allows players, either consciously or unconsciously, to forget that the experience is artificial. What components are required to create immersion varies from player to player; some may be immersed by an engaging universe, while others may be drawn in by polished mechanics.
Immersion can refer to how a game handles its world, or to how players actually feel while playing. Ludonarrative dissonance is often the largest obstacle when seeking to create or experience immersion.
“The player’s immersion in Alien Isolation‘s world is total to the point of suffocating, as environmental details, sound design and an engaging mechanical experience trap victims in virtual space.”