Each game is different, but i can decide if i will like a game within 30 minutes most of the time. A lot of the time, its within the first 10 minutes. Occasionally, the developers spent time polishing the first 30 mins, then you approach the 1 hour mark and things start going to shit.
A lot of us have played enough games that every sandbox feels the same, every first person shooter feels the same, every puzzle game feels the same (or whatever your favorite genre is, you know the pattern that they all have) so instead of "is this original game good" our focus is on "how is this game different or better that what I've already played"
In addition, you can almost always see what a game is going to look like 15-20 hours in within the first 15 minutes. If its an open world survival craft, the end game is a mega base. If its an RPG, the end game is a demi-god character. If its a story based game, the end game is finishing the story and maybe getting 100% collectibles and such. For me, I'd rather skip the time investment and try new experiences.
He's cooked?