Yes. I'm afraid many people, including developers, confuse game difficulty with frustration. For me, the difference is obvious: if there is something I must do that I fail at very often, it is hard, but if I must then go through a drawn-out process for a retry, then it is frustrating. Difficulty makes the game harder to complete. Frustration makes the game harder to enjoy. I can give a clear example of this:
In GTA 4 there are many sequences where a mission goes South and you'll need to escape a 3-star rating law enforcement. In GTA 4 Vanilla, I just went for the nearest shore, scouring for boats, because that was the only way I knew how to get away from a 3-star police rating or higher. In The Lost And Damned expansion, one of the earliest missions involves doing just that, except there are no boats nearby- I die, and I have to restart the whole drawn-out gunfight sequence every time, losing some of those precious grenade rounds I spent $700 a pop buying. My other alternative is restarting the mission completely, which means I'd have to do more each time. That is frustrating, and it limits my patience to two tries per sitting, before I move on to another game. This means that this weekend I didn't enjoy my game as I could have had, or if you ask me, should have had. The game, at that point is just not worth the trouble.
If you were to compare how difficult GTA 4 was to Commandos 3, you might as well compare the ferociousness of a kitten to that of a wolf. Yet, I was never frustrated by Commandos 3, which involved quick saving- every time I made a mistake I'd just revert to my last quick-save and have an immediate re-try. It only made me more excited to tackle the challenges of completing each mission, and Commandos 3 is one of the hardest games I've ever played. I would play it for hours on end without being frustrated, albeit taking days to complete a single mission.
The same thing happened to Burnout: Paradise. They recently updated it with an option to restart whatever event one might be on at any moment. So, when I see that I've lost the race, I no longer have to see the game tell me I lost and drive all the way back to the same intersection (which I won't remember anyway) to try the race again. Instead, I can get a quick few shots at it, losing as I must, easily attend to the thing, and enjoy myself better.
I like tough games. I like to make things harder, especially when they get tactically intensive, but I hate being frustrated. Since games are played for fun (well, if you ask me), then frustrating games will get less of my attention, and it's just a shame, because they could otherwise be great.
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I believe that back then, the norm used to be that games were harder and more frustrating. One would often have to restart a level completely if they failed at any point during it, as quick saving was not yet fashionable, or possible. A backlash from this culture produced the easy difficulties of more recent games, coaxing greater and greater markets into gaming and largely destroying the actual essence of playing a game: the negotiation of challenges. I hope that the popular response to this would be to produce challenging gameplay, without including factors which fruitlessly frustrate the player.