If, like me, you're terrible at Chess, how about the chance to jump across the board with a Shotgun? That's exactly what you do in Shotgun King: The Final Checkmate. Note: personal purchase.
Working out of the box with no issues found with Steam Play Proton, it's another small game that will end up sucking away vast amounts of your time and it's pretty cheap too at only £4.99. It doesn't have controller support but on Steam Deck, it has such simple controls it's practically perfect anyway with the trackpad.
The idea is that you were a rubbish King, treated your people badly and so they all left you (including your Queen) for the other one. Obviously you're mad about it and all you had left was your trusty Shotgun, so you decide to go on something of a Chess-rampage and battle your way through.
Runs don't last particularly long, so it makes for a fantastic coffee-break game but it's so delightful that you can easily lose a few hours to it too. So it's a bit like Vampire Survivors and Gunlocked in that way. What makes it especially good is that it has some of the basic rules of Chess for movements but adds the uniqueness found in rougelikes and the action too. Each turn you get to decide where you go, or who you shoot as you attempt to avoid a checkmate while also hunting down the enemy King.
After each floor you will also get to pick between two random cards, each giving an upgrade for you and the enemy to spice things up which is why it's fun to replay through it many times.
This is going right near the top of the pile for my regular games on both my Linux desktop and Steam Deck.
Available to buy on Steam.