The free-to-play games.
To promote Red Dead Redemption back in 2010, Rockstar Games created a Facebook dueling game titled Red Dead Redemption: Gunslingers. The game has long since been discontinued. These are a few files I still had saved from when I data mined the game for a Rockstar fansite I ran back in the day. Just a couple versions of the logo, the Flash SWF file that played short clips of the duel, and short 30 second music tracks it played. Unfortunately, no where near enough files to reconstruct the game, bu