Worlds - 3rd/1st person stealth/kill everything game with a rich story full of secrets and lots of content, mission based exploration of extremely varied environments. Multiple endings.
https://store.steampowered.com/app/304850/Worlds/
$1.99
his other game is pretty cool too, fun 1st person adventure with fast and impactful sword & shield combat in a strange world. lore is told on notes you find around the world. big surprise later on.
https://store.steampowered.com/app/1304400/The_End_of_Dyeus/
$8.99