Hard for all the wrong reasons.
But the game is too hard for all the wrong reasons: first, there aren't enough health potions, and they are too expensive when you get the rare opportunity to buy one. The save points are too few and far between, so if you die you have to do a lot over again. These two things shortfalls combine to slow the game right down; rather than moving through the very cool and well designed environments, most gameplay is just trying to do the same thing over and over again.
Also, the camera makes things quite difficult. Sometimes it takes a long time just setting up for a very easy jump.
This is a good game, don't get me wrong. It just would have been better if the challenges came from the game environment itself, and not the game design.