When a trophy/achievement includes "Beating the game on the Hardest Difficulty setting" and/or "Beat all challenges on Gold/Platinum (I'm looking at you, Prototype)"
Beating the game on Hard is OK, but when the game has 12 difficulty settings, there's a huge chance the last one is instead of being challenging, is just trial and error perfect bullshit.
Take Mass Effect 2 Insanity Trophy as an example, I'm currently doing my playthrough as a Sentinel Evil Shepard (First name, Fagballs) doing fairly well, and I cannot express how unbelievable annoying Scions are. They are, by all means, the hardest mob in all the ME2 universe.
There's one specific part in Horizon I remember redoing at LEAST 10 times because it had 2 Scions and an endless spawn of Husks (Which in Insanity, cannot be killed with Throw or Pull, since they have FUCKING ARMOR). I had to literally glitch the game to get through that specific part.
Stand near the door, to the left, and you can see a Scion aiming at a wall. Shoot Warp 25 times, and he dies. Go to the right side of the door, and you can see the other Scion, 25 Warps again, and you're done. I was so far away from them, their AI wouldn't trigger, so they were easy kills.
In short, fuck indie difficulty settings, I like Easy, Normal and Hard, and that's how it's supposed to be.