Does anyone know how busy it normally is?
We go every trip and find that it pretty much mimics the parks as far as crowds go. Quite honestly, I think the price of admission keeps a lot of people out.
Last September it was dead except for where there are usually lines (Astroblasters, Cyberspace Mountain, etc), but the lines are short.
In January, it was only busy on weekends and fairly dead on weekdays.
In March (St Paddy's Day) it was busy, but we were able to find games to play without trouble. At night it was filled with rowdy drunks that were a bit much to handle, but it was a drinking holiday.
In April (around the 20th), it was dead one day (the sunny day), but busy on a rainy day.
Usually we find specific floors to be more busy than others. Since you don't pay for any of the games, sometimes there are people who loiter on them for longer than one game. I'm totally guilty of this as well, but when I'm the one waiting, usually I just find something else to do.
There are pinball machines, skee ball, old-school video games, new video games, interactive games, air hockey, bumper cars-- basically the list goes on. It's a giant arcade. And they have a decent little cafe with food, soda, beer and wine for the adults. It's fun for the little ones and for adults.
We're in our 30's and love going. That being said, without our AP's and not knowing what was inside, we couldn't ever justify the $45 cost. Now after having actually gone, I think that if we ever did let our APs lapse, we'd still go to DQ even paying the admission-- we'd just want to stay longer than our usual 2 hours.