When you click on a monster to attack, and it moves out of your mouse player shouldn't be walking. You have to include kind of a locking mechanism, which would help A LOT!
I would add a Hint button which reveals a path for a random color 5/5 and that music! :)
I guess the solutions are not unique but even then it would help very much.
You can see how many times you played each stage when clicking on it (on the stage select screen).