Co-op first-person roguelike Barony is free to try on Steam right now, as players are being given all weekend to check out the full game's throwback dungeon crawling. The Windows, macOS, and Linux game is also on sale, so you can get it for half-off to continue your progress after the free period concludes. The weekend festivities celebrate the game's tenth anniversary as well as the release of a new version 4.3.2 update with a bunch of improvements including proximity voice chat. Here's a recent Making Barony: Origins of the Dungeon Trailer along with more:

You have entered the Barony of the vile lich Baron Herx! His curse has all but destroyed the town of Hamlet, and daring adventurers are the people's only hope. Prepare to face devious dungeons that demand your resourcefulness, wit, and vigilance. The dungeons are brutal; Full of vicious monsters and deadly traps, but legendary treasures, magical artifacts, spells and equipment will empower you throughout the adventure.