What a pretty game!! This is a really lovely concept, but I feel the low resolution doesnt wholly lend it self to the visual novel medium.
My only real complaints were the text bubble sounds (they were a little grating), and the fact to click on a star it had to be PIXEL perfect. I have a more sensitive mouth so that was a little hard haha.
Good job, and good proof of concept :) I can also see this being a cool tool to teach people constellations