Very good mechanism based on rules that change randomly but that is less frustrating than other games with the same concept as the rule change linked torebounding on colored tiles is an good way for the player to understand what easily what will happens next. The controls were a little confusing at the begining but when I understood that the ball was loosing its horizontal momentum after each rebound it was fun to play. The difficulty is challenging but may hard level happens a little too soon. May be making the ball less sensitive (going to the left/right more slowly) could smooth the diccifulty.