This game ain't bad, to be honest.
Pros:
-The music. Oh god, the music. It's perfect, and fits in the game perfectly.
-The little details. How this flower gains color when you get it back from the rainbow, how the fire pillars get transformed into water when you get the dark blue color.
-Good starting storyline. Rainbow is gone, get the colors back! Simple, everyone can understand what's going on in this game.
Cons:
- EXTREMELY linear. The whole game is 'follow the gems, and you'll find the exit!'. I had more trouble finding some doors to the levels then to complete the levels. I would've liked a bit more challenge, some hidden gems. Like, the Exit door open when you collect 90% of the gems. The remaining gems, the 10% left, could've been more hidden. Would give the game some replay value.
-Although it's self-explainatory, I would've liked to see a bit of a tutorial in the Flight Mode. At first, I thought you had to collect ALL gems. Then, I understood it was only the color gem you had to get. Also, there seems to be a small consequence when hitting stones, that would've been useful to know prior-hand as well.
-So when you get all colors, you cannot go play levels again? You have to restart the WHOLE game? Yeah, that's a bad thing if someone is a completionist and want to get that 1 gem (s)he didn't get in 1 level.
- No development in the game. Okay, you collect back the rainbow colors. But nothing after the prologue.
- No difficulty change. It seemed to me that all levels were equally easy, and the only thing that changed was the number of gems I had to get.
That's my 2 cents on this game.