I always call DisneyQuest "five floors of hell"...but that is from my viewpoint. It five floors that are dimly lit with video game crap and noise. The walls are rounded and have these weird, curved angular things that jut out to form halls. It is as annoying and alien a feeling as I'd like to have at WDW. Lights flashing, kids zipping around. It's a feaking nightmare, as far as I'm concerned.
For a 12yo kid into gaming, it is heaven. Kids immediately get the surroundings and find their way around quickly. They love it. If you take a 12yo who is into video games there, it will probably be the far and away #1 Highlight of his trip.
I left mine there after about an hour so I could shop. I said I'd be back in an hour, but was late and so worried about it. I got back to the Car Driving game and was waved off. Those car driving game kids sit down and they don't get up. And they take no prisoners! They came to play! They knock each other off the road and they all have a blast. I asked if it would be okay for me to leave again for two hours and got a very distracted, "Yeah. okay!"
When my son was his age, he wanted to be a pro ball player or a pizza delivery guy when he grew up. He occasionally said engineering because he figured then he could be one of the guys who blows up (implodes) buildings. After visiting DQ, he decided he wanted to work there when he grew up. All that other stuff was tossed out the window. And that went on for quite a while.
He just finished college and has decided to go to law school. Looking at costs, I brought up the old idea of working at DQ. He chuckled and said - he is 22 now, btw - that it would be great, but it wouldn't pay very well. (Still, it would be great.)
My nephews went at ages 10 and 12 and also rated it as the best thing Disney has. The older one, who loved Test Track and rode it six times said, "Test Track was good, but...". The younger one said that he didn't want to choose between Dinosaur and DQ, but DQ was his favorite. I told sis that we should just send them in, but she had to see what I was talking about for herself. We were there for maybe 45 minutes before she said, "Get me the {*+% out of here."
Going to DQ is the best thing you could give that kid, IMO. If you love your child enough to enter that hell, that is.