it's hard to say bc I don't really think of characters this way, personality and story significance always trump visuals to me. a character can look like an utterly boring nobody and still be a favorite because the story around them is interesting

but when I have absolutely no context as to a character's personality or story significance there are certain things that make them "cute" or "cool"

things I find cute: bright colors, simple outfits, or really glamorous outfits sometimes, short straight hair, dresses and vests, animal ears

things I find cool: wonky weapons or tools, striking color palettes, utterly unrealistic hair styles, anything shiny or glowing, emblems representing the character or faction

i also like nice, simple, iconic designs. like most nintendo characters