A Solitaire Mystery is a collection of over 20 unusual solitaire cardgames, ranging from somewhat standard rulesets playable with a traditional deck of cards to mysterious experimental takes on the genre and funky reimplementations of other games in solitaire form. Among other things, ASM makes you grow and harvest plants, defeat eldritch monsters, perform alchemy and play poker over the course of its solitaires.

Each solitaire included has a difficulty rating, and each solitaire tracks your victory streak so that if you enjoy a particular entry a lot, you can try to go for multiple victories in a row! The game is fully mouse-driven, and includes settings to e.g. enable more lenient undoing and utilize a specified random seed to allow trying the same deal multiple times, or even share it with your friends.

A Solitaire Mystery was included in the 2025 Experimental Games Workshop at the Game Developers' Conference.