"Casualties: Unknown," an ultra-detailed, grueling survival sim, has been released. Players must manage not only their limbs and mental health, but also their "cardiovascular system.""Casualties: Unknown," an ultra-detailed, grueling survival sim, has been released. Players must manage not only their limbs and mental health, but also their "cardiovascular system.""Casualties: Unknown," an ultra-detailed, grueling survival sim, has been released. Players must manage not only their limbs and mental health, but also their "cardiovascular system.""Casualties: Unknown," an ultra-detailed, grueling survival sim, has been released. Players must manage not only their limbs and mental health, but also their "cardiovascular system."