There is an online game on pbs here
Great for early math perfect for pre-k and k level, here is what an educational newsletter says about it:
Skills: shape recognition
Description: Construct castles without getting sand in your shoes with this nifty shape game for early learners. When sand shapes are revealed, players "drop" them into the outlines of simple sandcastles. A message of congratulations appears as each castle is completed, and two levels of play are provided.