From Ghost Ship Publishing and Game Swing, GUNTOUCHABLES is a new frantic online co-op doomsday roguelite for 1-4 players. For 24 hours from the release today it's also free to claim and keep, so act fast and grab it right now. Otherwise, it will be $4.99 from tomorrow after 9am UTC.
More about it: Guntouchables is a 1-4 player co-op roguelike doomsday shooter where every second counts. Impeccable teamwork and wise decision-making will be key to beat the overwhelming odds when facing the ever-changing enemies of the wasteland. Complete mission objectives and collect UpCrates for Cash and Perks that will increase your chances of survival in the wasteland as difficulty gradually escalates. Between each mission, players must vote between a random selection of mutations that will grant enemies new traits and abilities. Fortunately, this choice will also offer the players immediate or long-term benefits, making the decision less obvious but more critical.

Direct Link
While it's officially out now, it seems they're planning lots of upgrades for it. Perfect game for Steam Deck, SteamOS and Desktop Linux as it runs with Proton.
What are you waiting for? Go grab it.