Hello
this is an opinionated list of free or very cheap games available in various games stores.
Epic store
Filament
Solve challenging cable-based puzzles and uncover what really happened to the crew of The Alabaster. Now with Hint System (for those ultra tricky puzzles).
I have not played this game yet but a good logic game is a good logic game.
Rising Storm 2: Vietnam
Red Orchestra Series' take on Vietnam: 64-player MP matches; 20+ maps; US Army & Marines, PAVN/NVA, NLF/VC; Australians and ARVN forces; 50+ weapons; 4 flyable helicopters; mines, traps and tunnels; Brutal. Authentic. Gritty. Character customization.
I have played it for a short of time and this is not your CoD or Battlefield type of shooter but still a very good realistic one, although the game is quite old now.
Humble Bundle
11-bit game studio
Ok, this is great. I have played 3 out of 9 games of this bundle and This war of mine and Anomaly are very famous games and they are great.
Train Simulator
OK, these is not my usual games but for fun, I belive they will be great and worth every penny out of £20 for the bundle.