Work is still ongoing on IFDB’s estimated play time feature, but as of right now, 198 games on IFDB have an estimated play time! Thanks for adding your times!
I recently played 16 Ways to Kill a Vampire at McDonalds and decided to enter my playtime as an hour and 50 minutes (roughly how long I spent killing the vampire in all 16 ways and unlocking the final scenes). According to the guidance on IFDB, I should have put it as 10 minutes (how long it took me to figure out how to kill the vampire once). But I thought that would do the game a disservice by making it look a lot less substantial than it was.
I think you going completionist and putting your time to reflect that is ultimately more helpful than ten minutes. It means that some people will spend longer than ten minutes interacting with this game, but some people will be satisfied with one ending. When the average eventually evens out, it’ll better reflect how much time someone might spend (probably unlocking a couple endings).