Use KEY WASD to scroll across the map. Click to select and place a tower. There are 6 different towers, 4 have special effects. Blood is how much damage you can take, you die if it reaches 0. If you are quite confident and ready for the next wave challenge you can hit next wave button to send the next wave early and get bonus money. Before the game, you can choose the map you prefer at first, and then into the game, you must hold the pirates out of the home.