Combining the classic game of Billiards with various news rules and roguelike features, Drop Pockets is set to arrive on August 8th. Developer Children of Madness has a demo up for it on the Steam page, and it has Native Linux support.

Direct Link
Highlights:
Billiards like never before - There's a lot more to Drop Pockets than just pool balls. From hockey pucks to the planet Jupiter, each ball has the power to carry your run or stop it dead in its tracks.
Sharks in the water - Pool Sharks wait at the end of every round, ready to cut your run short by applying new rules to the table. By changing physics, adding obstacles, or just flooding the table with balls, these bosses demand your best.
Trinkets and baubles - Rack up your points and get rich quick with items and upgrades. Combine dozens of Chalks, Racks, and Cues for many potential builds and ride your highs to success in Drop Pockets!
Right now the Linux demo is an empty download on Desktop, as the developer has set it for Linux and Steam Deck. An annoying issue Valve should really solve. A well-meaning feature for special Steam Deck packages, but confuses developers. If developers set Steam Deck on a content depot package on Steam (even if Linux is ticked too) it results in it being only available for Steam Deck. I've let the developer know.