Relaxing, but gameplay is not clear

I find this relaxing to play, but there is no explanation on the objective or maximizing your score. Im guessing gold stars are worth more points, but it escapes me as to how to actually achieve them. It cant be speed, but it isnt accuracy either, as missing some will get you gold, and sometimes a perfect trace will get you purple, or even a red. Please update your tutorial or at least add a more thorough and more accurate description to your app page. Given the variability in outcome, Im guessing that the game is actually just pretty buggy and its almost irrelevant what path you trace.

New cacher about Personal Zen