Wire up sfx, Sega Master System palette for win/end screen, add start screen

scenes/start_screen.gd

@@ -1 +1,26 @@
 extends Control
+
+func _ready():
+	if EventBus.debug_starting_floor > 0:
+		call_deferred("_start")
+		return
+	get_tree().paused = true
+
+func _unhandled_input(event):
+	if event is InputEventKey and event.pressed and not event.echo:
+		if event.keycode == KEY_SPACE or event.keycode == KEY_ENTER:
+			get_viewport().set_input_as_handled()
+			_start()
+		elif event.keycode >= KEY_1 and event.keycode <= KEY_9:
+			EventBus.debug_starting_floor = event.keycode - KEY_0
+			get_viewport().set_input_as_handled()
+			_start()
+		elif event.keycode == KEY_0:
+			EventBus.debug_starting_floor = EventBus.STARTING_FLOOR
+			get_viewport().set_input_as_handled()
+			_start()
+
+func _start():
+	get_tree().paused = false
+	EventBus.game_started.emit()
+	get_parent().queue_free()