Like handing out free samples at the mall. Except with monsters and zombies, obviously. One is an asymmetric team-based co-op shooter, where a small bunch of regular humans take on a giant hulking beast. The other is a team-based co-op shooter, where a small bunch of regular humans take on an inordinate amount of zombies. Asymmetrically. Evolve, Turtle Rock's four-vs-one shooter, has been out for a little over six months. People were a little skeptical of the idea at first, the match-making could be a little unreliable and the DLC only served to piss people right off \u2013 the devs claim that they didn't have time to get everything into the game for the initial release, but the general public felt it was a cash-making scheme \u2013 but the game is actually a lot of fun once you get going. That's what Turtle Rock are banking on, because this weekend they're hoping to real in a fresh batch of players by hosting an Evolve free weekend for PC and Xbox One. Free weekends aren't unusual on Steam, but seeing them on Xbox One makes a pleasant change, and you've still got... about two days left to get your fill of the Evolve free weekend. Sneaking into the same time-slot as the Evolve free weekend is Killing Floor 2 and the story there couldn't be more different: Currently in Steam Early Access (in an effort to get the game as mechanically perfect and well-completed as possible before release)\u00a0Killing Floor 2 pits a group of six humans against a pretty much endless supply of zombies, or Zeds as they're known here.\u00a0It's still asymmetrical, but it's definitely humans-vs-AI here, so matchmaking and fairness isn't so much an issue for Killing Floor 2, but making it as fun as possible clearly is. Both these games will clearly live or die on having an active population to play, which is why we're seeing the developers dangling their fishing lines in the water to try and tempt more players into the fold. Even so, the Killing Floor 2\/Evolve free weekend is clearly a great way for people to try before they buy and make an informed decision on games they'll probably invest a lot of time and money into. More of this, please. Enjoying your Killing Floor 2\/Evolve free weekend? Then why not pick up Evolve from Amazon now, or the Killing Floor 2 early access from Steam.