UBOOT is a Second World War game set on a German submarine. Thing is, you're not controlling the boat. You're controlling the men who control the boat. Inspired by games like Fallout Shelter, UBOOT is a game where "You look after their physical and mental health, because if the sailors are hungry, tired and their spirit is low, there's no chance of winning even a skirmish."
This also sounds very cool:
It is important to balance the overall discipline and trauma of your crew. If you are a harsh captain, the level of both goes up. When trauma is high a secret feature of each sailor can be disclosed. It can reveal his alcoholism, make him go berserk, he can also turn out to be a coward or a spy.
The crew are made up of individuals, each with their own story and personality, and while your decisions made through the game won't change the outcome of the war, they will change the outcome for your men.
I also like that UBOOT is going for mechanical realism, letting you wander the boat and see how each part of a U-Boat actually functions.