Go & Connection Games
Nexus
Capture like Go, win like tic-tac-toe, and pay for every capture.
2 players
Boom is a bug.
Peace Cat Games makes thoughtful board and card games with a twist you won't find elsewhere: debts for captures, a third side that keeps the peace, stones bought with stones, and scores on the complex plane. Every game starts with a short introduction.

Go & Connection Games
Capture like Go, win like tic-tac-toe, and pay for every capture.
2 players
Go & Connection Games
Go, where you can buy extra stones by removing your own.
2 players
Chess & Variants
Chess with a third side: the Cats keep the peace.
1 player, taking one of the three sides
Card Games
Hearts, scored with complex numbers.
4 players
Math & Discovery
Mutate a quiver until every vertex turns red, and hunt for rules nobody has proved yet.
1 player, with community leaderboards