Funding and labor for the first phase of the renovation came almost entirely from local residents, schools, and businesses. On Friday, Doyle Elementary delivered a $5,000 check that put the castle over its $150,000 fund-raising goal.
Phase II calls for giving the castle a pirate ship feature to accommodate children under 5 and those with limited mobility. Phase III - which drew big cheers from parents in the crowd - would add bathrooms.
But Sunday focused on the finished renovation, not the additional fund-raising to come.
Karen Birmingham, who served as cochair of middle school outreach for the Save Kids Castle board, said middle-schoolers "are the perfect age because they grew up with it when they were little. But it's still fun, they still get excited to go in."
Her daughter Ashlyn, 13, helped clean, sand, and repaint the knights, princesses, dragons, and mermaids that decorate the castle. And she'll help staff the booths at the castle's Halloween festival Oct. 26.
Ashlyn, who used to go to the castle once a month or more, said it was a place to meet friends. "I remember playing tag in there with kids I didn't even know."
"Once my shoe got stuck in the rope," said Ashlyn's friend Gabbie Van Saun, adding that the castle is much safer now.
In addition to smoothing the wood and repairing the safety nets, volunteers added two huge twisting slides, climbing rocks, and a pneumatic elevator pole. The slides were by far the biggest crowd-pleaser Sunday.
Christina Shalaby of New Hope rode one with her son, Cooper, 3. Soon after, 5-year-old Ellie Shalaby came shooting out, gleefully laughing and jumping and begging to go again.
"It's twisty and fast!" said Ellie, her brown curls bouncing. "Can we do it again?"
For more than three hours, kids rotated in and out, and the lines for a simple wooden castle remained at near-Disneyland proportions. Nearby, hundreds of other families visited the day's special attractions: an arts and crafts tent, food trucks, and children's musicians. They played with a giant rainbow parachute and cartwheeled and rolled down hills.
Now a sophomore at Hatboro-Horsham High School, Jenna Yorko, 15, got some of her classmates and volleyball teammates to work on the castle through the GOTCHA Club (Get Off The Couch with Healthy Humanitarian Activities) that she founded four years ago.
Jenna's a little old for the castle now, but one thing lured her in Sunday: her 7-year-old brother. "I got to go find him," she said, looking only half-reluctant.