Write game description

README.md

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 # Kace
 
-The tiny incredible breakout game.
+A small multi-ball breakout game where accuracy is required.
+
+## Game description
+
+Aim, shoot and combo! Try to high-score before you are overwhelmed by bricks! Each time a ball hits, the brick life amount is decreased by one, and you get a score point. When the brick is destroyed, you get a new ball for the following rounds until you loose. Each round, a new row of bricks is generated. So, aim wisely and try to maximize shoot efficiency!
+
+## Controls
+
+- Use mouse to aim
+- Left click to shoot
+- Click again during a round in order to instantly collect every ball and start next round
+
+## About
+
+Two games of this game where concurrently developed : this one is made with Godot engine, the other one was made with Haskell by a friend.
+