What can I say? Outstanding, fantastic, superb game! Challenging, but definitely not frustrating. And what is most important: totally logical. There is a path to solve every level, you just have to find it. On some levels you may even find an alternative way to pass it. I wish that the author would return one day to make even the 4th part. I only currently don't have enough patience to go for all the skulls.
Sometimes you can have a feeling that the hit detection is a bit off, but maybe it's only because of the fact that for example your jump wasn't that perfect?
There is also a small performance issue, you may get a feeling of the game missing a frame, but it is rather the flash player/plugin issue and its worse and worse performance.
Oh, did I already say that this game is awesome too? If not, I am doing it right now.
Go play it and twist your brain and test your both hands' skills at the same time!