The phrase "immersion factor" refers to how deeply involved or engaged someone feels when they are participating in an activity or experiencing something. It measures the level of captivation or absorption in a particular situation. Full definition
I think that itself adds to the whole immersion factor of games these days. (stevivor.com)
Wind and road noise are both present and accounted for, contributing to the all - important immersion factor. (gtplanet.net)
Given some of the things showcased in the trailer, it's possible that they'll want to leverage the extra horsepower from the PS4 Pro and Xbox Scorpio in order to extend the visual immersion factors with longer draw distances, smoother frame - rates and increased post-processing effects. (cinemablend.com)