Ketchup is a simple abstract game with a devilish dynamic. The goal is to have the largest group of stones on the board when the board is full of stones, but as you get closer to winning, your opponent gets more powerful. Whereas most stone-placement games are about position, Ketchup is about timing, position, and the interplay between them.
Designer's Page for Ketchup
Ketchup was a finalist in the Thousand-Year Game Design Challenge