There are many first person shooters out there, and once upon a time it was also really popular to create WW2 action games. Lately the industry has moved on, and the titles with a focus on WW2 have been less, and less over the years.

However, a dream of mine is to actually make a WW2 game, and a FPS no less. With a focus on the story, art and war. The issue is that usually FPS games, and action games in general tend to avoid really depressing or sad moods, as they tend to have bright shades to let the player continue with the flow.

What my vision is... Is the vision of a game that tries to take one of the darkest times for humanity and showcase all sorts of emotions, experiences, violence, the strive for peace, despair, death and life through the experiences of a German soldier in WW2.

Picture the heroism, the feeling of glory, the achievements and slowly let the whole mood desaturate as more destruction is witnessed, more death, rumors, secrets and denial, and the truth. To achieve this whole vision, the retelling would be done through the use of appropriate classical music, and an art style that lets 3D blend as art, but at the same time attempting to be using a realistic gameplay for damage, challenge and amounts of enemies.

I don't think it would be a "fun" kind of game that will make you go "woo, look how I killed that guy!" but rather a game that allows the player to explore a game that gives different reactions based on the different moods of someone's story.

Nowhere like that. Inglorious Basterds is actually something really far away conceptually.

Inglorious basterds: the game

No, Spec Ops is also a direction I would like to avoid.

Like a WW2 era Spec Ops: The Line?