Hello there, this archive that I have sent contains 12 levels that can be used as a prologue to the levels in the 'alien' folder, or as a separate levelset. I tested all of the levels to make sure that they are challenging enough but still beatable. I also feel like that the first 8 levels could be complemented with a worldmap and for the whole levelset, multiple .story files could help create a more professional user experience.
*Now included is a levelset icon for if the levelset is made a separate one.
Notes:
$ All of the space* levels use music that does not come with the default Pingus installation. Different music may need to be used.