I will not embellish, this game is incredibly difficult. I also found it to be greatly satisfying whenever I finally beat a level or boss I had been stuck on for a while. To be brief, If you don't enjoy this game, you probably don't enjoy video games. Definitely pick this up for a rent, buy it if you really enjoy it.
This games has the worst controls of any platformer I've ever played. When you let go of the stick, Kong continues to move a while. When you press jump, it takes about half a second to register. Between the 2 of these, it's almost impossible to do any precision platforming.
But the rest of the controls are similarly bad, with most moves locking you into their animation until they finish.
I thought my wife was upset over nothing when she quit playing it... It's one of her favorite series, and I figured it was just a little too hard for her. Nope. It's just plain awful.