Even though your castle is on an island in the middle of nowhere, using your ships you can not only trade goods and become richer with all the products you create, but also spread your control over other territories by sending battleships to attack harbors and other islands, as you are about to discover.
How to play "Sea Force"
Space: Jump. Up-Arrow-Key: Accelerate. Down-Arrow-Key: Brake. Left-Arrow-Key: Left . Right-Arrow-Key: Right