I'll be honest, I expected the game to be way harder based on what people were always saying all the time.
I think the truth is that the difficulty of the game was pretty much the standard many years back, but games have been getting easier as each gen passes by. Nowadays, we're getting spoiled with easy games, lots of checkpoints, in some cases easy saving of games (Fallout 3), and being able to rewind(Grid, Forza 3). Had DS been released on somethin like SNES, I don't think it'd be as infamous for it's difficulty like it is this gen.
There definitely are some pretty damn hard parts in DS but for the most part, I think the game takes more patience than it does skill. Definitely not saying it doesn't take that much skill though - it takes both lots of skill and patience to get through, but if I had to choose between the two, I'd say more deaths will happen due of a lack of patience. In many situations, it'll also force you to consistently play good.
Of course this is all assuming it's your first playthrough though....
As soon as you hit NG , shit gets real :z
