The submarine

Torpedo Mission:

An allied submarine just vanished from your radar! The enemy is still lurking… you have to locate them and to arm the torpedoes to retaliate. Do not forget to resurface once you have secured the perimeter.

Deepdown Mission:

Explore the seabed on board of your faithful U-53. Unfortunately, the engine gives out and you are sinking inexorably to abyssal depths. There is only one solution: to manually restart the engines before you run out of oxygen!