Special Unit

Here are some special units:

Empire of Japan

 * Kamikaze, cost 200M, maximun build 20, can instantly destroy one destroyer or crusier, and need two to destroy a battleship or carrier

United Kingdom

 * Super Battleship, same size as Battleship, attack 25, cost 2B

United States

 * Super Carrier, same size and cost as Carrier, maximum build 3, can carry 20 aircrafts

Nazi Germany

 * Super Tank, same cost as tank, oil cost 5, maximum 20, attack +10