added pause menu in level and ability to load levels from main menu

src/game/levels/level.gd

@@ -21,6 +21,8 @@ extends Node2D
 ## reference to the line node used to draw the finish line
 @export var finish: Line2D
 
+@export var menu: Control
+
 signal distance_changed(new_distance)
 
 #variables
@@ -31,6 +33,7 @@ var lap_distance = 0.
 var start
 var finish_right
 var finish_left
+var paused = false
 
 # Called when the node enters the scene tree for the first time.
 func _ready():
@@ -53,6 +56,10 @@ func _ready():
 
 # Called every frame. 'delta' is the elapsed time since the previous frame.
 func _process(delta):
+	
+	if Input.is_action_just_pressed("pause") && running:
+		pause()
+	
 	if (running):
 		# shrinking the track
 		width -= shrink_factor * delta
@@ -86,6 +93,16 @@ func _process(delta):
 		distance_changed.emit(get_total_distance())
 #		print_debug("player distance driven: ", get_total_distance(), " distance since last check: ", off_diff)
 
+func pause():
+	if !paused:
+		Engine.time_scale = 0
+		menu.show()
+		paused = true
+	else:
+		Engine.time_scale = 1
+		menu.hide()
+		paused = false
+	
 
 func update_line():
 	line.set_width(width)