>>724551329
Depends on the genre. For JRPGs, I require a minimum of 60 hours. Fatigue tends to set in around the the 110+ hour mark depending on the game. The only one in recent memory that exceeded this cap was Xenoblade Chronicles 3, with 154 hours.

Barring the exception of RPGs or visual novels, most single player experiences I indulge in barely hit the 30 hour mark. The sweet spot seems to be around 15 - 25 hours. If it is your typical linear third person over the shoulder stealth/shooter or "sad dad" game - that's generally the amount of time it takes for me to get bored. It's similar for horror games as well. Except I am less "bored" and more psychologically drained. Was shocked viewing my old SH3 save and seeing my first playthrough was only 8 hours but it felt like an eternity.