Main
That means that mob scene is non existent. It is supposed to be a reference to the scene file. For example
onready var mob_scene = preload("mob_scene_name.tscn")
That should be at the top of the script file above the func _ready().
If you look at the bottom of the screen, you'll see that the variable "mob_scene" is already declared at line three. You can only declare a variable once, so you should probably delete line three. You'll also have to change "mob_scene_name.tscn" to the actual name of the scene file that is the mob.
The player is not eliminated when the mob touches him.
