Ever played a game that even after numerous tries, you can't beat that one level? The one that's really long and has no checkpoints, or the one where if you make one error you lose and have to restart? The one where you strategically move your player, but realize you forgot something and have to go all the way back to get it? The ones where you just want to scream at the top of your lungs?!
Discuss those here.
I'm currently playing Osmos, a "eat or be eaten" game, and there's a group of levels where you have to navigate very slowly, and bumping into any of the massive things around you kills you, and you have to move around in a certain way using only a little bit of "fuel" (propelling yourself makes you smaller). If I make one small misjudgment in propelling myself (you shoot mass to propel yourself, and that mass bumps into other masses and makes them grow), it sets off a chain reaction, making one mass absorb another mass until it takes up the whole screen and it's impossible to win. >:(