This was really perfect ! I really like the puzzle design, they were just hard enough to be quickly solvable once you found the "trick" for that level while constantly keeping that satisfying "Finally, I solved it !" from level to level ... although I am not really sure I understood how I managed to solved that end-game level with the two looping tracks...
Anyway, I enjoyed it greatly and would love to try more levels if they are of the same quality. Good job !