Added shield and score UI; player collision signal connected to enemy

scenes/player.gd

@@ -1,5 +1,12 @@
 extends Area2D
 
+signal died
+signal shield_changed
+
+@export var max_shield = 10
+var shield = max_shield:
+    set = set_shield
+
 @export var speed = 150
 @export var cooldown = 0.25
 @export var bullet_scene : PackedScene
@@ -26,6 +33,18 @@ func shoot():
 func _on_gun_cooldown_timeout():
     can_shoot = true
 
+func set_shield(value):
+    shield = min(max_shield, value)
+    shield_changed.emit(max_shield, shield)
+    if shield <= 0:
+        hide()
+        died.emit()
+
+func _on_area_entered(area):
+    if area.is_in_group("enemies"):
+        area.explode()
+        shield -= max_shield / 2
+
 func _process(delta):
     var input = Input.get_vector("left", "right", "up", "down")
     if input.x > 0: