Take chess, reduce one side to only the king, fill him with a terrible wrath, hand him a shotgun, then watch him go. That's Shotgun King, a roguelikelike turn-based shooter where units (mostly) move like chess pieces, only our lone king has a shotgun. It might sound like a throwaway joke game but Shotgun King is an interesting and fun challenge, especially when your upgrades also bestow different buffs upon the opposing army. And it has a free early version so you can have a go yourself.
Shotgun King sees the black king abandoned by his court and even his queen, because he was a jerk. He decides to leans into this, and sets out delivering the deadliest checkmate across 12 levels. The white side field most of a traditional chess army (though this will grow and change), while you have only your king and his royal shotgun.
Every chess piece has its traditional moves (helpfully, you can mouseover units for a reminder), though white will move multiple pieces each turn. And the black king, well, each turn you can move then empty his shotgun's barrels. It has a spread arc and range limit, so your movements are about aiming as well as avoiding checkmate. Seeing as you only need to kill the white king, you might do well to attempt assassination rather than clear the board—especially as ammo regenerates only slowly after expending your initial reserves. But slaughter can earn you 'soul' cards granting one single move as another unit, and upgrades might give you whole new moves.
After each level, you have a choice from two pairs of permanent upgrades, but only one upgrade is for you—the other is for white. Your half of the pick might buff your shotgun with better stats or extra abilities, or give your king new moves such as a magic wand raining damage or a 'Taunting Hop' which damages the white king when you bounce over a unit. On the other side, White's half of the pick might let their pawns attack in all directions, or replace one bishop with two knights, or give regular reinforcements, or... it's an interesting decision, shaping the builds of both sides. I've sometimes avoided great upgrades for myself because the flipside was too strong for white.
While I know little about chess, maybe that helps here. Because I have few preconceptions of what pieces 'should' do, I'm not thrown when they gain the ability to behave in strange new ways. Yes, it is good, actually, that I'm ignorant of one of the world's most venerated games.
Indie duo Punkcake Délicieux initially made Shotgun King in under 72 hours for the Ludum Dare 50 game jam, where it was declared the overall winner. Emboldened by its success, they took a few weeks to expand and polish it for a paid version, Shotgun King: The Final Checkmate. That has brought a new story mode, balance tweaks, a makeover, and new units and weapons and things. But you can still download the initial game jam version for free, as a demo of sorts to see if you like the basic idea.
Shotgun King: The Final Checkmate is available now on Itch.io DRM-free for $6. The original jam version is still free to download from that page too. The Final Checkmate is due to land on Steam in May, and the devs say they'll give Steam keys to folks who own it on Itch. It's also available as the current reward on Punkcake Délicieux's Patreon, which costs £3/€3 a month.
But I do wish it wouldn't show me the story intro again every single time I open the game.