This is a great game and even though the prototype version was on PC, it's the kind of game that was made for touch. TCHOW is a great indie dev, I've played a few of his other games, and Rainbow is probably one of his best.
Wouldn't really call it a puzzler, maybe an action puzzle game, but it's more about maneuvering and finding the best path through each maze like level. The game offers a nice amount of replay value, as each level has four objectives: simply complete the level, collect all stars, complete the level without lifting your finger, and complete a level only splitting your rainbow X amount of times. You can play each level multiple times and need different strategies for each of those objectives
The art style is wonderful, it's challenging but not unfair (you can always see where your path is going to lead you), and the developer plans to add more content depending on how well the game does.