Blade of Agony is such an excellent game. It's free and delivers much more than other games sold in the market.
You have a long and lengthy campaign with different environements and different ways to play it. You have "fantasy/sci fi" missions when you hunt for old relics, or infiltrate super german bases, fighting against zombies, mutants and so on, like what you can see in a Wolfenstein game. And you have military missions where you are in the forefront of WWII battles, fighting the germans on foot and with vehicles, and other missions infiltrating bases, like what you can do in a Medal of Honor/COD game from the late 1990s/early 2000s.
This game should get a spotlight on GOG. It's a great tribute to classic WWII shooters.
There are a ton of games out there nowadays and like many, I play a game, complete it, and go for another, but Blade of Agony is one of the rarest titles I replayed after completing it, because it is so good. It is definitely one of my top 5 games from the 2020s I recommend to anyone.