I finally finished Dragon Age 2 on Nightmare after over sixty hours logged in the game. Recorded, anyway... not sure if it counts time played if you reload. Either way, it was a long fucking game. I did every side quest that came my way (except Gamlin's thing in the third act, I think it bugged on me). I am glad to finally be finished with this game.
And that's not to say I didn't enjoy it... I did (mostly). However, in hindsight, I wouldn't have played it on Nightmare. I love the challenge, and Nightmare in DA2 was certainly a challenge, but most of the time it was a "What the fuck? Bullshit!" frustrating kind of a challenge.
What makes Nightmare mode incredibly difficult in DA2 is only partially that the enemies have more health, and do more damage (and that you're limited to three health/mana/stam potions at a time) etc. The biggest challenge, I found, is that Nightmare mode completely alters the entire way you have to play the game, and not in a good way, due to friendly damage.
The game was clearly not designed with friendly fire in mind, because once you take it into account, half of every character's abilities immediately become a liability. I chose to play a 2H warrior/berserker, which turned out to be possibly the biggest offender of all. All of the warrior's special abilities in the 2H weapon tree affect the area around him. In fact, just your basic swings with a 2H weapon cleave a wide arc of damage around you.
I could not even begin to count how many times I one-shotted Aveline with my warrior's Mighty Blow ability because she was too close to the blast radius. That poor Mabari Hound was vaporized by the same ability even more often. I couldn't even take the Whirlwind or Scythe abilities, because they were too indiscriminate. Mighty Blow at least I could sort of aim and control.
Same thing goes for Varric's Bursting Arrow, or Hail of Arrows. Any AOE damage ability in the game becomes as likely to hinder you as it is to help you. And you can't exactly cut AOE out of your gameplan, because you aren't left with enough single-target abilities to get the job done.
So for the majority of the fights, I had to micromanage my party very closely to try and minimize the amount of damage I was doing to myself. Often it was just unavoidable.
Now, none of this really bothered me all that much while I was playing (at least not until the final act). It was frustrating as all hell, and there were some fights (High Dragon, fuck you) that took me a day or two to finally get past, and there were some fights I had to leave, and come back to after I'd leveled up some. When I finally did get past the fights, there was that great feeling of accomplishment and satisfaction that is the reason I play games on the hardest difficulty now. It made the struggle and frustration worth it.
However, I said that in hindsight I wouldn't have played it on Nightmare, and here's why: After I was finished, out of curiosity I loaded up an older save and set the difficulty to Normal. It was like night and day. I could use abilities more freely, in fact I barely had to pause the game at all to issue orders. I no longer had to worry as much about what my stupid AI companions were doing, because they were not so fragile, and if they idiotically fired an AOE blast at their feet, they wouldn't slaughter all of us in a single shot.
It really opened my eyes to just how much this game was clearly designed for Normal mode, and how much adding in Team Damage on Nightmare mode had sort of "robbed" me from experiencing half of the game's options for abilities and spells, etc.
Add in that there is no achievement for completing the game on Nightmare or not changing the difficulty at all, and I felt a little let down. Not that the achievements are the only reason for playing the game on hard, but it's always nice to get a little trophy for the accomplishment.
A game like Demon Souls is hard, but never felt to me like it was unfair. Dealing with DA2's sometimes stupid and downright self-destructive AI companions, and one-shotting back-stabbing enemy rogues with an endless supply of health potions, did not give me the same feeling.
On the other hand, from what I understand, DA2 was rushed out the door to make a buck (as is clearly evident in the repetitive environments, a subject for a whole different rant), so I suppose I shouldn't be too surprised.
All in all, I did have fun with the game, but I doubt I'll ever be tempted to play it again, even on Normal. I think I visted those 5-6 different zones enough times for six play throughs.