A considerably great concept but terribly executed. The idea was fine, and the gameplay for most part was good. My two main peeves about this game are
1.) It does not allow you to save, so it makes it inconvenient if you have to stop playing to go do something important. It does not matter if you are level 20 on all the Distance, Bouncing and Learning Skills, it will reset back to the original stats if you quit.
2.) The repetition gets extremely tedious and takes the fun out of the game. Games are not supposed to be chores. Real life exists for those chores. However when you have to repeat every single level from the beginning every time you die in a game, it is not fun anymore, it just gets boring, and unnecessarily demanding.
Concept-wise, it is lacking. It seems you had the general idea of collecting crosses and evolving, but for what reason? There is no purpose. Maybe if there was a purpose for all that repetition then it would have been bearable. Checkpoints would indeed be useful in this game, it will further improve the concept.
This game is not good as it is. It is extremely lacking. The lack of a mute button is also a problem. The music could get annoying repeatedly playing over and over.
On the plus side, the graphics were good, and fitting for the simplistic concept of the game. Overall, the game is just a shambles. It's a concept that's not fully-realised. When I saw the 1-star reviews I thought the game could not be that bad. Well, it was not that bad, but it was not so good either.