Whoa, I did it! 'A' was the hardest, 'B' and 'C' were easier and better done. Here are the problems with A:
Chellanges are quite repetitive in a screen. In most screens there is little to no time factor, which means it's just a couple of similar chellanges joined together. When there is a time factor (you can't rest between chellanges), it makes much more sense. Making the last chellange the most difficult one is a bad thing, and here on all the screens of A path the last chellange is at least one of the hardest.
In B and C challenges were more creative and GFX of B was very interesting.