Lead and Gold: Gangs of the Wild West is free to play this weekend on Steam as well as on sale for 50% off its normal $15 price tag. The game is primarily a versus multiplayer affair but it does offer a two player co-op survival mode called Gold Fever.
The free play session ends one hour past high noon on Sunday, that's 1PM Pacific time. Lead and Gold: Gangs of the Wild West was also released on PSN - sadly - you still have to pay for it over there to play it. If you're online playing this weekend, you should join our Steam Group to find other folks to play co-op with!
Source: Store.steampowered.com