#1. "Amorphous" aliens are aliens that are essentially pure cartoon, colorful blobs with random limbs and body parts added to taste (Google image-search "alien clipart"). They're fun, but very hard to take seriously, and just don't look believable next to a human being. Not good for my purposes.
#2. "Star Trek" aliens are what I'm calling any aliens which are most easily described as "Humans, but...". "Humans, but with pointy ears", "Humans, but with extra arms", "Humans, but with weird makeup on". I honestly don't understand the appeal of these, outside of live-action film where it's reasonable to want a human-being to portray the alien character.
#3. "Roswell" aliens are probably the most pervasive image of "Alien", and I kind of love them. They're cheesy and a little cute and a little repulsive. They're a bad fit for Softies, though, because they're just too iconic.
They are The generic image of "Alien", which is pretty bad for character and world-building. They also have such strong associations with crop circles, UFO sightings, and alien conspiracy theories, that seeing them outside of that context would feel alien (eyy). Alien life being at home in environments far from Earth is critical to Softies, and Roswell aliens just feel like they belong on Earth.
I'll get into what exactly does define Softies' alien design some other time, but I thought starting with what it definitely is not was a good introduction.
[This post was made public in July 2016. Become a patron to see a new one every week!]