Standing in front of the two Dumbos, you'll have the option of doing the standby line the right or, if you have a fastpass, taking the fastpass option on the left. Skip the fastpass. Your kids will love the interactive queue option on the right. We waited around ten minutes, sometimes less, to get into the play area. When you get up to the front, a cast member will ask how many are in your party and then hand you a pager. Now say, for example, you have a total 35 minute wait for the attraction. You'll spend around 25 minutes in the play area, turn in your pager to the cast member at the front, and then wait another 10 waiting for the ride. It might sound like a long time, but trust me: Your kids won't want to leave. And depending on the age of your kids, you'll enjoy sitting and relaxing on the benches.
There are slides, fake fireworks to shoot off, and plenty of things to climb and jump on. Do you see those netted areas up there? They're big enough for an adult to run around in too, so you can join your kids. There's a back stair behind the "burning" building in the picture above that grown ups can use if they don't feel like climbing up. There's also a play area for young toddlers right in the middle with seating for the adults. If your kids are 5-years old and up, they should be fine running around on their own. The ground is soft and there's not a lot of potential for accidents.
Just a couple of warnings. There's no restroom in the interactive queue. You'll have to turn in your pager to the cast member at the front and she'll give you a fastpass to go through the other side of Dumbo once you're ready. You'll go out the back door and walk straight over to the Storybook Circus bathroom, which is right next to the train station. The other issue is the back door. The play area holds 175 people. With that many kids and grownups running around, it can be difficult to keep up with your kids. Since no one is manning that door, it would be easy for a small child to open it and walk outside. I'm hoping to see some measures put in place to change that, as the potential for some sort of incident is there.
I think this is one of the smartest things I've seen come out of Disney Imagineering in a long time, turning the long wait times for Dumbo into fun. I literally couldn't get my kids out of there. And that, may be it's only fault, which isn't a bad one to have.