Dark Souls, as I'm sure by now you've heard, is hard. Very hard. Right from the tutorial-free opening you're punished relentlessly, and every time you overcome a impossible enemy you can be sure something even more brutal awaits around the next corner. To this end I cannot recommend it to all gamers, especially if you've never played an action-RPG. However, those with patience and determination will find it an immensely rewarding experience.
The game drops you in at the deep end, starting with your character breaking out of an 'Undead Asylum'. Your encounters here initially seem difficult but pale in comparison to what waits for you ahead. Your travels will take you to many varied locations ranging from a castle and its vast grounds to underground swamps, and most of these environments look stunning. Sometimes the visuals can admittedly look a little rough around the edges, but the sheer scope of the game more than makes up for it. Unfortunately the frame rate suffers in larger areas, especially in 'Blighttown' where on more than one occasion it broke down to the point of being unplayable.
Everything takes place in one colossal world where if you can see a location then chances are at some point you can go there. The level design is mostly fantastic and often ingenious, with many of the worlds connecting with eachother to prevent the need for endless backtracking. This also means that one bonfire can sometimes serve as the starting point for several different sections of the game (the Firelink Shrine in particular is one you will be revisiting many times). These bonfires act as Dark Souls' checkpoint system and should you die you will be resurrected at the last one you visited. You can also use them to level up your character, reinforce weapons and perform various other actions. However, your only relief is also something of a double-edged sword as fallen enemies are also resurrected each time you visit one. To add insult to injury, your own death will result in loss of any souls you may have acquired (souls are essentially XP and also serve as the game's currency). You can retrace your steps to where you were killed to get them back but if you die on the way then the souls are gone forever. What initially appears to be an unfair and tiresome gameplay mechanic actually serves to keep things challenging, although repeatedly slogging through some areas on the way to a boss fight only to be killed and have everything respawn can become infuriating.
The combat in Dark Souls is precise and most importantly fair. Your character will come accross many fearsome and deadly opponents, but all can be defeated with patience and skill. With the exception of occasional bugs it isn't often that the game feels cheap.
Speaking of bugs, Dark Souls has its fair share. In particular in combat there is a bizarre glitch where one of your attacks will randomly be delayed until several seconds after you've pressed the trigger. This doesn't happen a lot but when it does it usually ends in disaster. The camera, while perfect at any other time can go completely insane in tight spaces, especially when walking along very narrow platforms. There is an optional part of the game involving your character balancing on branches as you descend through an enormous hollow tree trunk. Several times here I had been cautiously edging my way across a narrow branch only for the camera to randomly swing ninety degrees and send me plummeting to my death. These bugs aren't frequent and perhaps wouldn't be so prominent in a more forgiving game. It should be noted that I do not have my Xbox 360 online and therefore have not been able to download any patches, so I'm not sure if these problems have been fixed.
For all of it's brutal enemies, merciless checkpoints and rage-inducing platform sections Dark Souls is an incredible game. While much of your time will be spent in sheer frustration, when you finally do make progress the experience is satisfying like no other RPG I've played. You know that feeling in other games when you defeat the final boss and bask in a sense of your own brilliance? Every time you make it to a new area, defeat a boss, uncover a secret location, find a rare item or even make the slightest progress in Dark Souls you get that feeling. Granted, you might break records for the frequency of your swearing, but it's totally worth it.