TBH There's not much I would change, gameplay-wise, but what I would do (and I'd be willing to help here), is change the graphics and the screen-size (or at least have it scaled from the start). i would animate the Spots (or change them to something else) so that they have personlaities.
The one thing that i really don;t like is that the screen is too small for my liking and I don't enjoy the game as much as I should. Even scaling it by x2 would make a big difference, I'm sure. I did this for B'lox! and Guru Logic Champs. They were both designed for a small screen (320x240) and scaled x2 for pc. It gives the graphics a solid, chunky look, but it works well (IMHO).
Other than that there was just one thing - when you light up the possible move squares, the darker squares aren't as visible as the lighter squares, so it's not as obvious that you can move to them.
