I'm not sure how old your kids are but they may enjoy the pirate cruise. It's a two hour cruise on an 85 ft. pirate ship. They have a ton of activities for the kids like swabbing the deck, water gun fights, face painting and pulling up a treasure chest from the bottom of the gulf that's filled with treasure. The kids got about 3-4 items (pieces of treasure) each. They shot the cannon a few times and at the end of the cruise they got tattoos and actually my DH & I got one too, the kids thought that was great!. I'm a newbie and can't post links but you can search for pirate cruise in Panama City and it should pull it right up for you. There is also a printable coupon on the site.
I was just in PC for two weeks visiting my folks. I actually grew up there and as kids/pre-teens we loved Shipwreck Island. We also enjoyed the Maze but it can get pretty hot if you do it during the heat of the day. There is also an outdoor mall called Pier Park and they have kid activities there too. It's across from an amazing fishing pier in case someone in your party likes to fish. You can catch King Fish and Cobia from the pier and actually take it to a close by restaurant for them to cook it for you.
If you like outlet shopping there is an amazing outlet in Destin called Silver Sands. It's not too far of a drive from PCB. You can pull it up online and take a look at the stores to see if you're interested or not.
Let me know if you have any questions!