Adding initial game files.

ball.gd

@@ -0,0 +1,23 @@
+extends CharacterBody2D
+
+const SPEED : float = 300.0
+
+func _ready() -> void:
+	initialize()
+
+func _physics_process(delta: float) -> void:
+	move_and_slide()
+
+func initialize():
+	var extra_offset = 0.0 if randf() < 0.5 else PI
+	var angle = \
+		extra_offset + randf_range(-PI/3.0, PI/3.0)
+	velocity = Vector2(cos(angle), sin(angle)).normalized()
+	position = get_viewport_rect().size / 2.0 
+
+
+func _on_screen_exited() -> void:
+	# update score
+	# reinit after 1 second
+	await get_tree().create_timer (1.0).timeout
+	initialize()