It REALLY depends on the type of game. Some are statraisers like TMGS and can take me less than two days (sometimes one) to finish a route, if using a guide, and it's the type of game where skipping is pretty widely used on replaying so the time is cut down further on future routes. (o゜▽゜)o☆
If it's a really story heavy game, sometimes I space it out over a few days just to settle into the story further than just zooming through.
I also get fatigued from playing otome especially when it's very monotomous or overdone storylines so my time slows to a trickle, if not fully stops. (ˉ▽ˉ;)...
I'm an avid criminal of not finishing a game because it's not the right "time" for myself to enjoy it. Bad moods, certain times of the year, there's multitude of reasons that a game one person finishes within a day can take others a lifetime, haha. (๑•̀ㅂ•́)و✧