I love it! but I have been having problems with the asteroids spawning on top of the player, A way you can fix this is by putting a tag "Player" on the ship, then in the asteroid script add:
func _ready():
var player = get_tree().get_first_node_in_group("Player")
var distance = (player.global_position - global_position).length()
if distance < 10:
queue_free()
Hope this helps!