I found this on my youtube recommendations. It looks like a pretty cool game, very similar to Battlefield, but free and singleplayer. The bots are pretty funny but brutal . I've yet to try it, but here's a video showing some gameplay of it.
--->https://www.youtube.com/watch?v=lqKxBnkYUf8

Here's the game page for it, including a trailer and downloads.
--->https://steelraven7.itch.io/ravenfield