In a sense, time is the universal currency for all games. Players only have so much of it available, so many life demands that take some of it, and so how a game works with or against their time matters a great deal as to whether they wil continue to play.
If the game requires that players all play at the same time then it significantly restricts how many players and which kind of market will play. Whereas if they can play at their own pace, that broadens the appeal enormously (and is why single player is the great innovation of videogames).
Time significantly changes the parameters of workable game design. Issues of being able to synchronise play sessions, remembering to take a turn and so forth are also all issues of available time. Issues of whether the majority of play is synchronous or asynchronous, contemporal or atemporal also matter hugely.
Time is one of six creative constants that apply to all videogames.
