Solitomb is a demon-fighting prototype which mixes Balatro and solitaire, from the maker of Slipways
Slipways was the best grand strategy game I'd played in years, because it tossed out all the genre's micromanagement in favour of a strategy puzzle where all your exploiting, expanding, et ceteraing could be squeezed into an hour's play. That game began as a PICO-8 prototype by designer Jakub Wasilewski before being polished to a fine shine in its full release.
All of which is just lead-in to talking about Solitomb, a solitaire-based dungeon crawler in which you fight demons by building hands of playing cards. It's currently - heywaitaminute - a pay-what-you-want PICO-8 prototype by designer Jakub Wasilewski where "all money earned goes towards making the bigger version possible." Like Slipways, it already seems like a frightfully clever piece of design.