We went to Disney Quest for the first time on our last trip. My kids loved it! I would say that as long as they are old enough to play video games like Play Station 2 or something like that, they would enjoy Disney Quest. I don't think very young children would like it because you have to be able to follow the directions for the games/activities.
Some of the things you can do:
Design a roller coaster by choosing the loops and turns in a computer. Then they put this program that you create into a simulator and you actually 'ride' your roller coaster (so be careful how 'loopy' you make it).
Ride a pirate ship. On this you are in a room with your group (my family of 4 wa on one ship). Someone steers and the rest of us shot at the enemy. That activity was our favorite.
There is a raft ride that you sit in a rubber raft and you have paddles and you paddle through what you see on a screen (they even have water spray out at you for effect).
There was a recording studio where you pick lines for a song and in one part you record part of the song, and then you can (for an extra charge) buy the CD (yes, we bought it

).
That have an art studio area where you can make pictures that can be printed out (again, for any extra charge--if you have them print them out).
There is much much more. There are these cars like bumper cars that you ride in and shot at the other cars (a Buzz Lightyear theme). And well, at the moment, those are all the details I can remember. To be honest, I am not a 'video game' person, and I found a comfortable seat in the cafe and DH took the kids around to a lot of it without me.
Anyway, my family could have stayed ALL DAY (my girls are 10 years old--twins).
Here is a website you might want to look at to learn more:
http://allearsnet.com/btp/dqfaq.htm
Hope this helps! Have fun!
DJ