There is no admission charge to Boardwalk. There are a few midway games and some street performers that the kids might enjoy, but the main draw is the night clubs, ESPN sports bar, and restaurants. You can also rent surrey bikes. It's fun, but I'm not sure there's enough to keep little tykes interested. You might want to venture over to Fort Wilderness. You can visit the free petting zoo (pony rides $3), and visit the blacksmith shop. The Trail's End Restaurant is the best dining deal on WDW property. They serve comfort, kid friendly food at really good prices. To make a visit even more to FW even more fun, take the boat instead of a bus (or driving yourself). You can get a boat from Wilderness Lodge or the Contemporary Resort, that will take you directly to FW.