Deadly Hunter is a game that originally hit Steam with a $20 price tag, but shortly after release the developer, Leiting Interactive,  decided to make the game free. It's basically a wave based shooter, with a catch. First off, you're using a bow and arrow instead of a gun, and secondly it incorporates some tower defense type mechanics. You basically have enemies that approach along specific pathways. You can try to take them out with your bow, but you'll soon get overwhelmed if you don't start setting up traps. It's not a horrible game by any stretch of the imagination, but it's probably a good idea that Leiting made this a free experience. It's hard to have buyers remorse when you didn't pay anything.