A game you just have to play to appreciate.
Although, there are many dangerous enemies in the game, there are just as many awesome weapons and sets of Armour, spells, and miracles and what not to help you get to you're next destination. The apparel in this game is some of the best I've ever seen, with plenty of cool robes, heavy Armour, Scythes, katanas, and staffs to kick ass with. Now that doesn't mean you're going to have you're way with the bad guys, it only helps to finish a fight faster or stay alive just a little longer. The best way to beat you're opponent is to out maneuver them, and memorizing their movement patterns; timing is key to victory. There are no hiding spots to cheap snipe some enemies like runescape in here, everything is wide open, and you're enemies can go where you do. The game never feels cheap in any way, but I should mention that there is lots of lag in certain areas of the game and it is a problem. But it's never game ending like some other games (I'm pointing at you Bethesda)
As for the online features, I can't really speak for that; I almost always like to play alone. What little I did play was interesting, although it's not much of a game-changer. Aside from phantoms invading you're world, there aren't too many NPCs around to chat with. There is usually at least one or two throughout each dungeon or fort, and they all serve some purpose in one way or another. Some are merchants, although you can't sell anything to them; they do have useful things. Some are blacksmiths, who will upgrade you're weapons to make them even more powerful, or you can change them to a new class completely on occasion; they always carry a few items unique to them. And the normal NPCs almost always show up later on in different areas, usually searching for something or just getting lost. There are little side-quests here and there, although you won't have a log-book to keep track of them since other areas are impossible to pass through until later. They are a blast to play, and finding something new is always a pleasure.
Souls are the main currency in Dark Souls, their use ranges from buying, upgrading, and leveling up. There is also humanity, which can be used to strengthen you're bond with a covenant, add more flasks to a single bonfire, or even become human again. But, if you die, it all gets left in a blood-splat in the area where you met you're demise. And if you die a second time without recovering them, it's gone for good. Most of the time this shouldn't be a problem though. Seeing as you rarely have a large amount of souls to pack around anyway, and if you do there is always a homeward bone that will transport you safely to the last bonfire you checked in at. Overall, the game is only as hard as how you play. If you have a good combat style, or system then there shouldn't be any real problems. On some enemies you will have to make compromises and change it up, but that isn't such a big deal. So if by now you haven't gotten to play it yet, or just don't want to be stuck dead somewhere in the game and feel like you've been ripped off; I can assure you there's no need to worry. And if you really enjoy a challenge or just want something fresh, then there isn't a better game out there.