It's hard to say specifics. I tended to like the levels that combined the switching of colors with movement. While frustrating it was rewarding to master. So levels that had colored rectangles push you if you weren't the right color. And you had to balance that with movement and switching colors. Best example might be level 7. Well the not "shortcut" part of the level. My least favorite ones were when you would prevent color changing and instead force me to rely entirely on avoiding obstacles. I very much enjoyed the concept of learning when and where to change colors and lost some interest when forced to stay a color and just learn the patterns. Hope that helps!