DROP - Each stone is dropped on an empty cell, next to and below a stone of the same color
MOVE - First player drops one stone at the first turn, then each player drops up to two stones (he may pass).
GOAL - Wins the player with more stones on the bottom row.
Some words from the author: For some time now [Apr 16, 2001] I have been toying with the idea of trying to model/abstract the flow of water carving out a mountainside. A related geometric pattern is the fractal on certain seashells. [...] The image in my mind is a root-pattern forming or tributaries of a river. [...] The game generalizes to any MxN board. Without more experience playing and "figuring it out" I don't know how M and N affect playability. My intuition suggests 8x8 (really 8x15 if you measured it at the bottom) is already nontrivial and 10x10 might be "tournament".
