I found Runescape to be a very involved game. It seems to me to be a complicated version of a Nintendo game my brother used to play when we were kids, Link. In that game, you also had to move around a magical world performing tasks, collecting items, and fighting creatures. However, if memory serves me correctly, it was not nearly as involved as Runescape seems to be. I found it pretty easy to get around for the most part, although, I did have a slight problem trying to figure out how to run. One of the things I found most surprising was the fact that with many of the simpler tasks, all you have to do is point and click and the computer suddenly takes over and makes your "avatar" do the task. If I remember correcty, the games of the early 1990's force you to assist you character in doing each task. (Whether it was swinging an ax multiple times or clicking each time you wanted to shoot an arrow.) I nearly got killed at first because I wanted to tell my character where to shoot the arrow and instead, she would move in the direction I clicked my mouse.
I understand now why the teens like to play Runescape so much. I believe it is actually good for them. It takes their natural desires to play and gives them a chance to think. It isn't for me (I prefer the socializing that comes around a normal, ancient, Nintendo where both players are sitting next to each other.) but I can see why the kids like it and I would probably encourage it with our library teens in the future.