When i was a bit younger (21yo now). I could play for 8+ hours at a time. I remember playing assassin's creed III in two sittings in 2 days time, and finishing mass effect 1, 2, & 3 in about a week. Now, I'm usually maxed out at about 2-3 hours. Depends on the game as well. I mostly play TCGs and rhythm games now. I sometimes play shooters but that's only once or twice a week. There are a couple games that I can spend more time on like the souls games but i still don't usually play for more than 4 hours at a time with those.