Yes, and in fact I'm trying beat it right now.
The game is Prinny 2: Dawn of Operation Panties, Dood!. I think it's a fantastic platformer, it's difficult, but in a good way, and it's funny.
Trouble is, when I first got it, I managed to get near the end, and hit a brick wall. I simply COULD NOT beat the boss rush near the end. Oh, the boss rush itself wasn't really the problem. It's what comes after it. You have to beat 100 clones of yourself. In one sitting. And if you die, the count resets, and you have to try and beat them all ALL over again. The difficulty of the game jumped like it found a cobra in it's toilet.
Despite this, I couldn't bring myself to get rid of the game, I still thought it was great. I'm actually in the middle of trying to beat it again. Hopefully, I'll figure out some kind of trick this time to beating that damn boss rush.