"10 Indoor Playspaces for the Smallest Philly Kids"

Lilypad South Philly
Another South Philly option, Lilypad offers open play based on age group throughout the week, as well as new-parent meetups. Bonus: They’re also the people behind the popular semi-annual City Kids consignment sale, and have recently extended that endeavor to the all-year Lilypad Thrift shop that you can visit in their basement space three days a week (plus monthly sidewalk sales). Your first visit to play at Lilypad is free, and then drop-ins are $5-$10 per family (or $100 for an annual membership).
$5-$10, 1234 South Broad Street.