Windmill is an interesting game with simple rules played with two decks.
The foundation is a single pile at the center. It starts with an ace and builds up in value, regardless of suit. After reaching a king, you can place another ace and continue building.
Above, below, to the left and to the right are wings with two cells. These start with random cards. You cannot build on these, but can move cards from them on to the tableau or foundation. Empty cells can be filled with any card from the waste pile.
The tableau consists of four piles that start empty and lie in between the wings. You can place a king on any empty tableau pile and build down in suit.
The stock contains the rest of the cards. Click it to turn one card over on to the waste pile.
You can play waste pile cards to the tableau piles, fill an empty cell in the wings, or play directly to the foundation pile.
You can turn over the waste pile when you have run out of cards.