This game is a play on the suddenly popular Dota 2 mod "Auto Chess". Instead of a chess board with entirely different mechanics, this uses a Go board. On each turn, the player gets a choice of 1 of 3 pieces randomly selected. Once placed, the opponent places a piece and the pieces all fight each other (by shooting projectiles). When a projectile hits an enemy, it damages the enemy player, which you can see by the red and green heart bars which match the pieces on the board in color.
There are 4 different pieces, each of which can be rotated in the 4 cardinal directions. An attack will be launched in the direction the piece points for each turn it remains on the board. When a piece takes 1 heart worth of damage or more in a turn, it is removed from the board.