Military shooter Over the Top WW1 has a free Steam playtest right now
Open link in next tab
You can try this new WW1 shooter with 200-player battles for free, if you’re speedy
https://www.pcgamesn.com/over-the-top/free-steam-playtest
If you love games like Battlefield 1 and Isonzo then Over the Top WW1 should be on your radar with its huge battles, map editor, and more.