A few minor comments:
1. I've become used to having a fullscreen option and missed it here. While clicking around trying to find one I skipped past the initial letter (which is kind of hard to read in a small window) and then couldn't get back to it to see if there were relevant clues there.
2. Maybe needs a bit more contrast on the zodiac clues; even once I twigged what to look for I had a hard time reading them. Or maybe I'm just old. Yeah, I'm just old.
3. In the initial letter, "it's" should be "its", more than once. Have a care for your players' OCD, man!
Otherwise, short but fun.