H-sniper: World War II is single player war game but it is not of normal soldiers. The soldiers are anime girls.
There is a free DLC for 18 and plus due to the soldiers are naked on the other team. This game is a fps and personally I love it since it is very easy.
This game is a simple with bullet time and it basically tells you where you short them at. It also is nothing but endless waves so have fun with this game and it is very cheap.