This is a good word search game with a twist. It's funny how such a simple game gets more insteresting by tying it to another concept, constellations. I like the atmosphere of the game, it's relaxing and inviting. As far as I understand, you're not guaranteed to be able to use all letters in every game? That would be a big improvement.
It would be great if you could use Enter to accept a word and Backspace to remove letters. Or maybe left clicking a letter again could let you deselect it and right clicking anywhere could let you accept the current word? Clicking those buttons on the top felt a bit cumbersome.
The game itself is pretty good, the UI could more intuitive :)