Use random to generate bricks

godot/scripts/Grid.gd

@@ -32,6 +32,11 @@ func generate_row():
 
 
 func generate_cell(x, y):
+	if randi() % 2 : # 50% of generation
+		build_brick(x, y)
+
+
+func build_brick(x, y):
 	set_cell(x, y, Tile.BRICK)
 	living_cells[Vector2(x, y)] = current_row
 
@@ -56,6 +61,7 @@ func move():
 
 
 func _ready():
+	randomize()
 	generate_and_move()