Demon's Souls has a multiplayer gameplay mechanic that lets a dead player join a live player's game to either help or hurt them. In the helping case, you use a blue sigil to offer yourself to be summoned by another player, and the two of you can play a level or boss cooperatively. In the hurting case, you use a red sigil to invade another player's world; the game finds somebody of a suitably close level, lets them know you're invading, and the hunt is on. Going to another player's world to help takes you there as a Phantom, while invading takes you there as a Black Phantom. If you successfully kill a boss while a Phantom in another person's world, you regain your life. If you kill the player you're invading as a Black Phantom, you also regain your life (if you don't, you lose a level).
So I was at the last level in the Tower of Latria. I had just killed the previous boss and died on the way to the last boss, so I figured I'd help another player defeat the boss I had just killed to regain my life and have a better chance at the next boss. I ran back to the area just outside the boss's door and threw down my blue sigil. After a minute, the game gave me the message that I was being summoned to another player's world, but it was as a Black Phantom, not a regular one. Thinking I had encountered some weird bug, I was surprised to see the screen fade into a cutscene depicting a magician summoning a Black Phantom, and then adoring its head with its own headscarf, before dying and turning black. Then the game faded back in... and I found that I was the Black Phantom that was just summoned. I was the final boss of this world. Sure enough, in a few minutes I heard the sounds of the last guardian on the stairwell outside die, and a player rushed into the room. I saw a boss health bar pop up on the bottom of the screen with the name of the world boss, but it was linked to my own health bar. I defeated the player with the help of some magic missiles undoubtedly bestowed upon me by my now-blackened summoner and benefactor, and a message congratulating me for killing a hero, as I regained my life.
Demon's Souls is a hard game. Every review seems to relish this point, but it's interesting to examine why it's a hard game, or more precisely, why everybody thinks it's so hard. The action-RPG combat gameplay is challenging; each enemy offers a different method of attack that must be analyzed and countered. There's no rushing in to a group and mashing the attack button. When you first meet an enemy, it can generally kill you in one to three hits, depending on your armor and what kind of attacks it has, so there's a sense of urgency to learn the enemy's attacks as quickly as possible. The threat of unknown imminent death is challenging.
But there's also a sense that death has a penalty. The main currency in the game for buying weapons, upgrading them, and raising stats, is the same: souls that you earn by defeating enemies. So you can be making your way through a level, earning souls and doing well, when you slip up and don't block just so, and you die and lose all your progress. That is, unless you can make your way back to the same point and reclaim your body, Diablo-style. But only your last corpse counts, so if you die on the way to reclaim that corpse that has five thousand souls on it, those souls are gone for good. The threat of losing your stuff is challenging.
But the death penalty is not really hard to avoid; souls are easily invested in levels, repair bills, and consumables. If you're just short of a stat increase and don't want to risk losing it by entering a new zone, you can easily return to an old zone and farm for a bit to make up the deficit. It's not difficult to avoid the death penalty with some forethought. Once you have 0 souls earned -- that is, you've spent them all -- there's really no risk of jumping into a new zone.
And really, while the combat action gameplay are well-balanced and elegant, it's nothing new; there's blocking, attacking, countering, and dodging, and as long as you're good at recognizing animations, you can predict them well enough. I'm sure any skilled or experienced gamer can figure out this stuff pretty quickly, especially with a little experience.
So what's the big deal?
The challenge is that the game demands mastery in order to progress. Most games you can kind of eke your way through; your first run through a level leaves with not enough health packs for the boss, so you restart a save and redo it, and then you have a good three shots at the boss, and you're through. Demon's Souls difficulty is due to a lack of save points. It's also a beautifully bleak world; there are no bright colors, no balanced gamuts, and not even any music. It's dark and scary and lonely. Progression towards bosses becomes a trial in and of itself. You might have to slog through hordes of enemies just to get a chance at a boss, and the first couple times you face one, it will probably kill you within seconds. We've gotten used to games being 'fair' and giving us save points right before a boss, but Demon's Souls does no such thing; you must master a level simply out of the necessity of getting through it in an efficient amount of time to have a chance at a boss.
Demon's Souls is challenging because it requires you to work. You can't play this game drunk, and you're not going to enjoy losing yourself in it after a long day at work. I've found myself taking weeks off this game to play more fun and regularly rewarding games like Borderlands, Dragon Age, and even Silent Hill: Shattered Dreams. But like a job undone, Demon's Souls keeps pulling me back. I'm fine with giving up on games and not finishing them because they're too hard or not fun enough. But even though Demon's Souls has been both things at various times, I feel the effort I've invested in the game demands justification. I'm driven to finish it, and that's making it a challenging game to put down.