You could brand it and make it into a domain for kids / young adults, or perhaps the title for a novel?
It's nice because of the contrast between a "star", which we automatically think of as bright, and "shadow" which is naturally dark.
If the "star" becomes a metaphor for a person, then "starshadow" might mean that they are slightly depressed, or alone, or not 100% somehow.
Personally, I like it.