Look on the website for current promotional discounts/specials.
If your kids like interactive/immersive RPG games, set aside extra funds to play MagiQuest. DD and MY DBF spent the time we had out of the water running around the hotel playing this. It was a LOT of fun. IIRC is was about $30 each for the wand and game?
They not only have mini-fridges in the room, they also have microwaves. Since the H20park is connected to the hotel, it's really easy to go back to the room for lunch/dinner. We brought beverages, snacks, and stuff we make or could heat up and that saved a lot in terms of meal costs - We didn't want to go offsite, so we did eat at the buffet for dinner one of the nights and didn't really find it to be outrageously expensive - though there are only us 3, so YMMV. We also went downstairs to their pizza place (not pizza hut) and got heroes that were so huge that we split them and had them for two days along with the salad that we made and brought with us and kept in the fridge.
We had a blast and have already booked our room for Feb break - they have a bounce-back discount - just ask at the desk.