Create main script

Main.gd

@@ -0,0 +1,9 @@
+extends Node2D
+
+export (PackedScene) var mob
+
+var score
+
+func _ready():
+	randomize() # Plant seed for random number generation
+

Main.tscn

@@ -1,4 +1,6 @@
-[gd_scene load_steps=2 format=2]
+[gd_scene load_steps=3 format=2]
+
+[ext_resource path="res://Main.gd" type="Script" id=1]
 
 [sub_resource type="Curve2D" id=1]
 _data = {
@@ -6,6 +8,7 @@ _data = {
 }
 
 [node name="Main" type="Node2D"]
+script = ExtResource( 1 )
 __meta__ = {
 "_edit_group_": true
 }