A very hard game to master! I tried to find a good pattern of when to press the button to launch the dot for the next letter but failed many times. I think what it was missing was a clear indicator of how well you're doing, so something like 40 letters left, or 5 letters cleared etc. just something to make it a bit more obvious as to whether or not you're doing better than the last turn etc. Maybe a best score saved and displayed in one of the top corners inside the box.
But otherwise a cool game.