I play a fair number of games. I guess a lot, by most people's standards. Like many people (and unlike many others, such as my wife) I don't mind getting frustrated by games. Sometimes I play games that are pretty ridiculously hard, and spend quite a lot of time trying to beat various parts against absurd odds.
The absurdity is often the source of frustration. No matter how good a game is by most measures, sometimes the things you have to do is unequivocally unreasonable. This can be some large number of iterations of some task, or it might be a very small timing window, or it might be a sequence of events that is too exact in its requirements.
For example, I've been playing Odin's Sphere lately. It's a good game. In fact, it's an incredibly good game. But I've died probably fifty times trying to beat the boss I'm stuck at (oswald, the shadow knight, and I'm mercedes, in case you're curious). i don't think it's even possible for me to beat him no matter how skilled I am. I'd have to go back and grind some levels to become powerful enough to do so. The failures and this realization are both kind of frustrating.
So it's nice to see games that aren't frustrating. Well, to be more specific, games that are hard but not frustrating. I've been playing Trials HD lately. The beginner and easy tracks are hard. The medium tracks are passable, but it's hard to get the "gold medal" in them. The hard and extreme tracks are utterly insane.
But I'm not frustrated by the difficulty. Even though I've died almost 200 times on a single track before managing to eke by, and even though I spent a full 2 hours straight trying to get a gold medal on a particular medium level track only to be foiled every time at various spots, I'm not frustrated. The game gives me the level of control and precision needed to lay the blame for the failures squarely on myself. Put a different way, everything that happens "makes sense." This tends to be true of most "physics based" games, where the physics are simulated accurately. This is just a very polished example of this class of games.