Never played Demon Souls. All I know is that the game super difficult and punishing and this looks to continue that trend. What's your goal exactly? Is it like a dungeon crawler and you're searching for equipment or a grind fest to level up? Is there a linear progression in the story or is it an open world and they just let you run wild? I've watched a few gameplay vids and can't really get a grasp of it.

You die. A lot.

More serious answer, and I'm going by Demon's Souls so some of this may be incorrect, but in Demon's Souls, there are five "worlds" broken up into levels, each with a boss at the end. Each world is pretty linear (1-1 goes to 1-2), but you can do a dungeon in one level (1-1, for example) and then decide you want to try another world, you can tackle the first level in another world (4-1 as another example) There are different types of equipment you can acquire on your journey, which are upgradeable. Your currency is also your experience. You can use soul points you collect to purchase items from a few vendors or use them to upgrade some stats. When you die, you lose all of your soul points, but you can regain them if you can make it back to your body where you died. When you die, you become a phantom, which means you only have half health (3/4 if you have a certain ring) You also have other players that can leave helpful messages or be summoned to help you out, and some players can invade your world and fight you so they can become human again.

Does that cover some of what you wanted to know?

You die. A lot.

More serious answer, and I'm going by Demon's Souls so some of this may be incorrect, but in Demon's Souls, there are five "worlds" broken up into levels, each with a boss at the end. Each world is pretty linear (1-1 goes to 1-2), but you can do a dungeon in one level (1-1, for example) and then decide you want to try another world, you can tackle the first level in another world (4-1 as another example) There are different types of equipment you can acquire on your journey, which are upgradeable. Your currency is also your experience. You can use soul points you collect to purchase items from a few vendors or use them to upgrade some stats. When you die, you lose all of your soul points, but you can regain them if you can make it back to your body where you died. When you die, you become a phantom, which means you only have half health (3/4 if you have a certain ring) You also have other players that can leave helpful messages or be summoned to help you out, and some players can invade your world and fight you so they can become human again.

Does that cover some of what you wanted to know?

The story is you killing the bosses and then killing the last boss, thats about it :D

You should probably just drop by the Demon's Souls wiki on GB to find the answer to your question.

Uh the point of the game is immersion and exploration, there is a story but it takes a back seat and you will have to search for it to understand it.  It is not a typical jrpg where some emo is going to wax poetically about his life in a 15 minute cut scene, more like you will have a 2 minute conversation with some dude who robs graves for a living about the hell hole dungeon you are both stuck in and it's history.  In other words if you want the story talk to the npc's, read item descriptions, pay attention to your surroundings, etc etc.  It is not going to be spoonfed to you but it is there.  
 
As for leveling there is no grind, not really anyway, you can sort of play it that way but it is your choice to do so you don't "have to".  The secret is mastering the use of the weapons and a combat style that works for you.  Once you get good at the game the fun in alot of ways becomes about discovering just what you can do with your character and what kind of fights you can win that when you started you thought were "impossible".  Like killing a demonic knight with red eyes at level 4 with nothing but a generic short sword.  That said there are items to loot, weapons and armor to upgrade, spells to acquire, levels to gain, a very detailed character customization system allowing for multiple builds based on different weapon types and fighting styles.  Etc etc.
 
Also there is a very strong multiplayer community based around the pvp elements of the game.  However you are going to have to go to other forums to get a taste of that such as the Atlus forums or the Demon's Souls Wikidot.  I will warn you though, the PVP community is very .... .... crude.  They are normally pretty rough around the edges and definitely have become "cliqish".  (sp)

Die. A lot.

Die. A lot.

Something like this: http://www.giantbomb.com/quick-look-demons-souls/17-1485/ 
Although, the GB crew were not exactly into this game for the most part and it has a high barrier of entry so be aware of that.

Demon's Souls also features some of the most buttery smooth responsive controls that I've experienced anyway. The gameplay is rock solid, graphics are great and it creates a sense of atmosphere and dread like no game I've played. Constantly crawling around the environments with shield raised waiting for the next ambush is a heart pounding experience, and it just feels so goddamn amazing and well earned when you finally defeat the boss of a particular zone and return to living form.
 
Demon's Souls isn't overly difficult or cheap, it just forces you to be cautious and aware of your surroundings. Rush in too fast and you will pay. It's like the old school video games of the 8-bit days. Every monster has a pattern that needs to be learned, and there are no saves until you kill the level boss. Death means going back to the beginning of the level and doing it all over again. 
 
Wonderful game all around.

Demon's Souls seemed like one of the most tiring and tedious games I've ever played... I actually ended up trading it in after only playing it for a couple hours. Some people get it, I suppose, and others don't. I was firmly in the latter camp. Not saying it's necessarily a bad game, since everyone else seems to think it's obviously awesome, but it made no sense to me and just wasn't enjoyable.

Dark Souls is looking like the same sort of deal from From software. If you enjoy suddenly dying and trying to learn from it every time it happens, which will literally be hundreds upon hundreds of times, then you may like it.

Slay demon's, collect souls.

fart  on monkeys

demon's souls was not difficult if you knew what you were doing.
 
the problem was that the game didn't tell you what you were supposed to be doing. 
 
i spent more time reading the wiki than i did actually playing the game. it was like a freaking research project finishing that game. i still don't know how the developers expected anyone to figure out most of that crap on their own. there's no way i ever would have finished it without looking up a ton of crap on the internets. 
 
but once you know what you're supposed to do, there's only 2 or 3 parts that are actually difficult.

Wow thanks for all that guys. A part of me really wants to pick up Dark Souls but I know I may get frustrated and just quit on it. It does sound really cool though.

Wow thanks for all that guys. A part of me really wants to pick up Dark Souls but I know I may get frustrated and just quit on it. It does sound really cool though.

@kishinfoulux said:

Wow thanks for all that guys. A part of me really wants to pick up Dark Souls but I know I may get frustrated and just quit on it. It does sound really cool though.

That would be dumb.  Just remember when you pick up the game to approach like you would if you were actually there yourself.  Not like it is freakin dead island or diablo.  The people who quit on the first level of demon's souls are the people who played it like it was a hack an slash game, it is not.  Like I said though part of the fun is realizing you died 54 times on your first play through then looking at your second and noting you only died 15 times, half of which were intentional.