feat: add game scene and player scene

scripts/player.gd

@@ -0,0 +1,10 @@
+extends CharacterBody2D
+
+const SPEED = 300.0
+const JUMP_VELOCITY = -400.0
+
+func _physics_process(delta):
+	velocity.x = Input.get_axis("ui_left", "ui_right") * SPEED
+	velocity.y = Input.get_axis("ui_up", "ui_down") * SPEED
+
+	move_and_slide()