VDO game, even as a form of mankind's recreational activity, has becoming one of the most significant evidence of intellectual composition which differentiates mankind from the rest of all other life forms on planet Earth.
This conclusion derives from how human brain can produce an emotional elixir "endorphine" while interacting with VDO game and its progress; While naturally, only sexual reproduction and/or few other similar activities may enable the brain to produce the wonder of such.
However, as abserd as it may seems by comparison; VDO gaming session may collaborately be initiated in the manner similar to those as described in the infamous "Karma-Sutra" as exhibit in equations below;

Single Player / Solo = Masturbation
Co-op / Limitation of 2 players per session = Monogamy
Co-op / More than 2 players per session / MMO = Group Orgy / Polygamy

This summarize my homeostasis theory about humanity progressive development in relation to VDO game evolution.
Thank you and good day to you. \(^.^')