I love my WWI and WWII history, so this one immediately caught my eye. I love your attention to detail, including the tunnel vision with the gas mask (though I think you used the wrong one), the damage, the general aesthetic, and the inclusion of the Berthier Model 1916(I could tell because it has five rounds instead of earlier models which only had 3). I would love to see a larger game and fully encourage you to continue expanding on it. The only thing I would change is maybe adding a few friendly French soldiers at the start to drive home that you're in the trenches; that way, when you start the fighting portion, you really feel that you're alone when you see everyone gone. I'm not a programmer, however, so it's totally up to you. Thanks for a great game so far!
I also recommend listening to Sabaton whilst playing. They're a great band who sing about war history.
I also discovered the gas mask you give the player looks to be a Ledershultzemaske (I hope I'm spelling that right). It was introduced in Germany in 1917. The French would have used an M2 mask. I don't think you need to change it, though. I just like talking about the specifics, so I remember them more. Last thing, (Sorry I talk a lot) you should check out The Longest Front here on Itch. It's a WWII shooter that I find really fun and Accurate.
So the gas mask in the game is this one: https://collection.sciencemuseumgroup.org.uk/objects/co148735/gas-mask-germany-1...
The british are dating the mask to 1915.
What you have seen is correct, the french soldier (the player) is also using the german gas mask. Thats because of crunch time. So we just used the same asset twice x)
But I could be wrong. Thanks for showing me that! I understand the time crunch, and if i'm being honest, I kinda like the german masks better