ENGAGEMENT
The quality and quantity of attention a player gives to a particular game, or the instilment of feelings of connection by a game. This can come in the form of enchantment–building a fascinating world–or retention–designing a system which encourages repeated play over time. It is generally quantified as hours spent with a game and frequency of return visits.
“Each instalment in the Call of Duty franchise maintains a significant level of player engagement by focusing attention on leaderboards and maintaining a drip feed of new multiplayer content.”