I am 24 and I still play, and I have friends, and family members who are 20 and up that still play, so no 20 is not too old to play. (there really isn't an age where your too old to play). --- Like a wolf, stalking its prey.
I haven't read the topic, but my opinion is that *almost* everything is alright in moderation. I'd say that as long as MH isn't the reason you wake up in the morning, you're probably doing alright. You really have to take it to the extreme for video games to become an actual problem. --- Safe and sound in its shell, the precious pearl is the slave of the currents.
I'm 23 and I have no problem playing games. If you feel guilty about gaming at your age, consider that gaming is something only our age group grew up with so far. Older generations look down upon gaming because they didn't have Mario/Zelda/etc. when they were kids. They don't fully understand. To them it's a waste of time, and they try to push out these vibes that games are for little kids and teens only. Wrong answer.
For the record I also read tons of books. I find that many books are a waste of time, which is ironic when you consider how reading has this intelligent/enlightening image about it. I recently stop reading Infinite Jest by David Foster Wallace (highly regarded book from '96) because I simply wasn't getting anything out of it. I hated the writing style, couldn't latch onto any characters, and only stuck with it for the occasional profound nuggets. Sitting through the last 500+ pages would've been--to me--a colossal waste of time, regardless of how much praise the book got.
So my point is, enjoy whatever it is you do. Don't pretend to enjoy whatever someone tells you you should do. --- ~Jacksonville Jaguars~
I'm 24 and still play video games. You might have to change what kind of games you play becuase your tastes will/might change. Although, I do not like the direction a lot of things are headed. I appreciate things like story and like to see complexity and depth. That puts me at odds with a lot of gamers these days who just want things to be more streamlined. Also, good production quality does not automatically equal a good product! I wish more people understood that.