We've played it quite a bit as hubby's brother and sister in law have it. We love it. A game can take at least an hour if not longer.
I think an 8 year old could play the basic game. There are expansion kits the get alittle harder which would probably be over his head.
You really aren't supposed to play the basic game with 2 people but hubby and I played it together today and still had a good time--much harder with two--but I won!
We've played into the wee hours of morning, we tend to start playing around 9 PM and can't seem to stop until 2 or 3 am.