Add some sounds

assets/sound/error_008.ogg.import

@@ -0,0 +1,15 @@
+[remap]
+
+importer="ogg_vorbis"
+type="AudioStreamOGGVorbis"
+path="res://.import/error_008.ogg-8e35fe844dea9a9ba58ee9b53471dbce.oggstr"
+
+[deps]
+
+source_file="res://assets/sound/error_008.ogg"
+dest_files=[ "res://.import/error_008.ogg-8e35fe844dea9a9ba58ee9b53471dbce.oggstr" ]
+
+[params]
+
+loop=false
+loop_offset=0

scenes/power_station.tscn

@@ -1,7 +1,9 @@
-[gd_scene load_steps=4 format=2]
+[gd_scene load_steps=6 format=2]
 
 [ext_resource path="res://scripts/power_station.gd" type="Script" id=1]
 [ext_resource path="res://scenes/coin_machine.tscn" type="PackedScene" id=2]
+[ext_resource path="res://assets/sound/forceField_004.ogg" type="AudioStream" id=3]
+[ext_resource path="res://assets/sound/error_008.ogg" type="AudioStream" id=4]
 
 [sub_resource type="CubeMesh" id=1]
 
@@ -21,4 +23,12 @@ mesh = SubResource( 1 )
 transform = Transform( 1, 0, 0, 0, 1, 0, 0, 0, 1, 0.0275149, 0.721019, 1.58046 )
 billboard = 1
 
+[node name="sounds" type="Node" parent="."]
+
+[node name="charge_get" type="AudioStreamPlayer" parent="sounds"]
+stream = ExtResource( 3 )
+
+[node name="error" type="AudioStreamPlayer" parent="sounds"]
+stream = ExtResource( 4 )
+
 [connection signal="coin_requirement_met" from="coin_machine" to="." method="_on_coin_machine_coin_requirement_met"]

scripts/power_station.gd

@@ -32,4 +32,9 @@ func collect_charges_from_station():
 
 func _on_coin_machine_coin_requirement_met(player):
 	assert(player.has_method("modify_inventory"))
-	player.modify_inventory("coins", collect_charges_from_station())
+	var charges = collect_charges_from_station()
+	player.modify_inventory("coins", charges)
+	if charges > 0:
+		$sounds/charge_get.play()
+	else:
+		$sounds/error.play()