“Length” of a game is useless out of context. Games like the later assasins creed are bloated garbage with overinflated playtime. On the other hand you have games with procedural generation, optional endgames, post launch content and the simple fact that a small, but still significant amount of players will play through a short game multiple times, because they enjoyed it so much/wanna get better. (In my case, thats Furi)
What I am trying to say is, you can’t really get a proper amount of hours of playtime for any game, unless its like 99% cutscenes.