I am amassing a collection of small spherical robots

Bonus:

And here’s my reference:

my claim is: multiple factors combined make the Peak Video Game Companion Form, and that these factors are...

SMALL. perfect size for holding, perfect size for tucking into your hood and snuggling, also makes you more likely to find them cute and feel protective over them because they are so small and vulnerable. (even spiky or extra-protective shells don't really fully dissuade this because the size of them remains the same)

NO limbs. ghosts are VERY expressive but because they lack hands and limbs they have to rely entirely on full-body movement & voice to convey this, which actually makes their gestures seem more exaggerated & obvious. (and of course the voice actors are just always knocking it out of the park; this is absolutely a big part of it) (nolan north especially like ghost's voice is CRAZY emotionally versatile)

and yet! despite their expressiveness! - NO features. an incredibly bold move by the designers to make the most lovable character & your full-time companion a guy with no features except one (1) IMPLIED eye. it's not even a real eye; it's a little image OF a ghost on a screen. this goes back to the previous point; that they're forced to be overly-expressive because they have no features like a mouth or eyebrows to convey something like a grin or scowl. (this ALSO creates a feeling of affection in the player, i think, because when they ARE expressing themselves it's always cute - again in large part because of how small they are & that their ONE feature is a LARGE eye (compared to the rest of their body). when they're happy they twirl their whole shell around, a particular favorite of mine is when ghost is angry and lowers his whole shell so that his eye is half-covered in such a manner it LOOKS like he's glaring. that's absolutely hilarious & adorable.)

entirely digital! i love that they're robots and i honestly think some of the appeal of them would be lost if they were creatures, like, a race of alien or something instead of a type of small robot. i think that what makes this such a good feature is that it creates a sort of distance in one way between the player and the ghost - we're not the same Thing, this is a robot and not a person, and so when they BEHAVE like a person (emotional! expressive! full of love and whimsy!!) it kind of bolsters the affection you have for them because it's New and unique; not, like, a pre-existing thing (like well yeah naturally they've got instincts and emotions and subjective reactions, they're an animal/person - vs., OH, they've got instincts and emotions and subjective reactions because even though they're a robot, they're still complex like a person!!)

also i can't not mention the overall shape language & design. there is an absolutely crazy amount of stuff going on in a design so simple. the symmetry is great, for starters - sometimes symmetry CAN be used to create unease by feeling artificial/unnatural, but in this case, the symmetry of the design connotates something easily-understood, reliable, safe, etc that puts us at ease. (this is also in correlation with the previous endearing factors such as size & expressiveness.)

continuing this, the shapes. the ghost is so satisfying to look at because it's made of shapes we find visually comforting & reliable - even when those shapes aren't actually there!

let me ask you this: the shell fins are triangular, right? nope! very few ACTUAL triangles on this guy! but the body is segmented in a way that makes it appear so. (this goes into actual shape language in the way our brains read it - we like odd numbers, because it feels more natural than even-ness and symmetry and perfect balance. part of the reason i think the ghost's symmetry is so appealing is because it is paired with these more "natural" shapes. (the fins LOOK like triangles, and they're actually 5-sided.) here, i even made diagrams:

also included in this one is the natural positioning. the design would be a little more disconcerting if the fins were positioned in an x instead of a +, and they almost are from the side, BUT even from the side, the middle fins still center a + shape to break it up.

last little detail regarding actual literal design is color. this one isn't AS big of a deal, especially because the shells are SO customizable, but i think it's worth mentioning that they look bright and shiny and smooth, BUT the particular white color of the shell is a scuffed, warm white, which again feels more natural and inviting. pairing it with the brownish-orange freckle (did you know the top and bottom tips of the shell are canonically called freckles??) makes it feel natural and familiar.

i also think it's worth looking at what is NOT a good ghost example. i found these pieces of concept art, including ghosts with their guardians, and what i believe is an early concept of the spider.

oh i am so glad these remained concept art. aren't you so glad that these remained concept art.

don't get me wrong, this is absolutely a viable character design, but FOR ghosts - for your lifelong platonic soulmate in the face of encroaching darkness?? for your silly sweet little guy??? absolutely not NEARLY as good as what we've been blessed with now. two eyes and a little mouth looking thing?? WRONG!! perfectly orbular shape?? WRONG!! that's not my guy!! (the perfectly round shells you can customize with ARE fine because you already KNOW the generalist design, and the one big eye stays the same.) and from this we can glean that the fins ARE important because they SUBSTITUTE as limbs, but this little circle body is just automatically less visually endearing and immediately seems like it would be less expressive. much to learn!)

SO. what now.

the main goal of me writing this whole thing is mostly to figure out what the guidelines here are so they can be adapted to other character designs - i have a similar concept to a ghost in an original project i'm working on, but invoking the same kind of loveability in them has proven insanely difficult. and of course, the context IS extremely relevant - a huge part of why we love ghosts so much IS dependent on the story, their role as a player companion, the significance of their connection to the player/player character (platonic soulmateism my beloved), and how they complement and contrast the setting of destiny. (part of the reason their symmetry and mechanical-ity(?) is so comforting because the rest of the world, especially the place where you first wake up, is so chaotic, broken-down & overgrown.)

also a quick but significant side note is that the fins are so much better than the ghost being small and round like a servitor (as the concept art seems to suggest) because it ALSO distances them from the traveler; despite being of it, they're not the same thing; they're their own beings who don't know everything it knows or even understand what exactly its history is. that round core and the white color draws that connection to the traveler, but the shapes and fins make them clearly their own things.

also, i genuinely think the name "ghost" is a part of this. categorically not what a ghost IS, but using such a simple word matches their vibe (& it feels white and cool and clean), and the word has an ethereal quality to it - i'd go so far as to say the connotation of it is sort of a longing or distance, invoking a kind of loss, which just ties everything about their lore together. (i LOVE when a simple, seemingly out-of-place word is used for things like this. phenomenal trope.)

so, we've got size, expressiveness, lack of limbs/features, and robotness. we got shape language and a very specific balance between artificial and natural. we've got name connotation. was this helpful? i don't know. if i had to list what to take AWAY from these categories to recreate the Ghost Effect, i would say...

size: keep them small. this one is not malleable, this is an integral part of the design.

expressiveness: over-expression GOOD, but works best when paired with a body/form that lacks things to express with (like features)

robotness: ???? maybe i'm mistaken and you could pull this off with a creature!! it kind of depends on the setting. if you wanted to try something like this in high fantasy instead of scifi, i would say the throughline should be something that you wouldn't expect to behave like a human; or something you would expect to be perfectly logical/calculated/efficient, so that that humanity & emotionality & personality really hits.

shape language: what is both distinct enough to clearly be its own thing, with shapes and patterns (symmetry counts as a pattern) that we find comforting but not overly-familiar? (also "distinct enough to be its own thing" is just a good rule of thumb for creature design in general - the silhouette should be clearly identifiable for maximum effect!)

artificial and natural: this ties into the previous item. unique & distinct but with some kind of sense of familiarity maintained

name: i think i've found my thesis, honestly, because this is, again, what is FAMILIAR but unique? what does it connotate? i think simplicity is an integral aspect of this, also.

THESIS/TL;DR/CONCLUSION: the Ghost's design is perfect because it is the ideal blend of something that is unique and distinct (and endearing) while also centering elements that are familiar to us in a comforting way.