Iron Lung

Set entirely within a claustrophobic one-man submarine nicknamed the "Iron Lung," you must blindly navigate an ocean of blood to take photographs of key locations, and hope whatever lives below doesn't find you. There is only a single porthole on the sub, and it needs to be closed due to depth pressure, so you have to navigate purely via an incomplete map, proximity sensors, sound, and a primitive external camera which can be used to take the pictures you need to complete your mission, or to get a grainy low resolution visual of what's happening outside. Success will require resourcefulness and patience.