It is difficult but the idea behind it is very cool. Was very surprised by the ending, but it still made me feel good despite it being in a way a sad one.
The only gripe I have with this game is there are a couple of instances during the man phase and the flying (more than a man) phase where pixel perfect jumps were required and cost you a lot of time if failed (which first timers and even some veterans are likely to do). These could have been made shorter and still be inaccessible during the previous phases to prevent "sequence breaking". It's only a minor gripe though.
Anybody who says it's too hard isn't really trying. I got the hardest pixels on the 4th or 5th try and the majority of the others on 1st or 2nd.