If I may make a suggestion for the storyline. It would be cool if the whole story and ending could leave it unclear whether the patient is actually possessed by a supernatural entity or if he is simply insane and his "powers" are just a figment of his imagination stretching only beyond what a sane person could do. A madman could think he is ripping an mythological creature to shreds with the power of his mind where in fact hes just beating up a security guard.
The characters backstory could be exposed by the demon and point to traumatic events that led to the possession. It will be up to the player to decide that what he sees is real or is it just whats in the patients head.
I hope you understand what I'm trying to suggest here. Think of the movie "K-Pax".
I think I get what you are suggesting, but I haven't a clue how to represent it without it coming out lame, like "Oh, but it was all just an illusion after all...".
The possible mental illnesses the patient has though is excellent fodder for Eternal Darkness-style hallucinations and mindscrews. The demon playing on his emotions and revealing his past to him in order to control him is another possibility. Even something really cliche'd like "Oh, it turns out I killed my whole family" could be pretty moving if the presentation is convincing enough. Though, I'm a very large opponent to cutscenes, and I'd prefer if the story were delivered to you through normal gameplay. It's just a matter of how.
Very interesting. Another thought, though:
Imagine that we can seperate the controls enough so that we can have a coop game where the patient and the demon are two (sometimes competing) humans. When they both want the same thing, then the human player controls what the human is actually doing, and the demon is doing something esoteric like "clearing psychic obstacles" so that the human can use whatever demonic powers he wants.
When they're in conflict, then there would be two possible states--human controlled and demon controlled. When the human is controlling the body, then the demon would be destroying or damaging "psychic centers" or someat, making the human hallucinate, have the controls end up loopy or whatever. When the human's weak enough, the demon could attempt to gain control of the body through some kind of duel-thing. But the damage doesn't get repaired through the game, so the hallucinations stick. Or maybe only repairs itself very, very slowly.
The demon controlled thing would be much the same, only here the human is setting up traps and creating defenses that would make the demon have to work even harder to clear psychic obstacles or whatever, which means that you'd be up against supernatural stuff with just punching for a pretty long while. So either way, everyone starts losing if everyone is disagreeing.
Then you could have two campaigns and a coop, but you'd have to have some way for players to communicate intelligently-maybe a pause-to-converse sort of thing, where one can shoot two or three replies back and forth, and then have to quit out to deal with whatever's happening in the real world.
I'm not quite sure what you're suggesting here. Is it that you feel it would be two-player, with one player having fun and another one playing a little minigame to get him powers?
Hmmm... it sounds cool.
If I can make the umpteenth sugestion: It would be cool to have the demon come in in a buisness suit while making vague references to freedom and such. The idea is that you are all alone, and this suggestively supernatural figure offers you a taste of power at seemingly no cost to you. As you accept more and more aggressive in his offers, clueing you in as to his true nature. I think that a fire and brimstone demon would detract from the game.
It's like you can see into my mind Chaoticag. I really like the idea of a business suit demon. In fact, ideally, he wouldn't be threatening at all, he'd just come up to him and say something like "Hey, it looks like you're really down on your luck. Tell you what, I really need some errands done, and you want to get out of here, so let's see if we can make an agreement..." and very early on he'd be very polite, appeals to your desires, use reasonable arguments to egg you on, and generally try to convince you that you NEED him to survive. For character development, as the game progress/as you make more deals, he becomes ruder, more insulting, becomes less reasonable, and is just pushing you along at any costs.
New idea: Instead of the deals coming one at a time, they're all available at the start of the game, and you can sign up to become an ultra-demon right from the first room.
However, this would actually be very counter-productive, as you'd attract the most powerful enemies in the game much sooner than you would otherwise.
See, what I'm thinking of is: that the entire game is a battle against the difficult curve. In normal games, the curve is linear, going up gradually as you progress, but what I'm thinking of is that instead of the curve being linear, it's
exponential. You'd be able to plow through with your current powers for awhile, but the difficult would soon ramp up to an unreasonable level, forcing you to consider the demon's deals in order to progress. So with each deal you make, you jump up considerably in power, and you flatten the difficulty curve, but with it being exponential, it'll last for awhile before jumping back up to unreasonably hard, forcing you to consider more of the demon's deals, and trading more of your humanity for ultimate survival. So if you did all of the demon's deals at the very start, you'd be very powerful, yes, but then the difficulty curve would jump up to unreasonable level VERY quickly, and you'd have no way to escape the difficulty, as there'd be no more deals to make, so the game becomes a dance to see how far you can get before NEEDING the next boost. Of course, ideally, while the game might become very hard, it would never be outright impossible, so self-imposed challenges like "Only take 1 deal" or "Max deals at start" would still be doable.
For example, at the very start, you have very strong demon arms that can overpower normal orderlies very easily, so the game ups the ante and throws alot of orderlies at you, so you need to make a deal to get super legs, so you can move and kick ass at a much faster rate. Then the game ups the ante and throws policemen with guns at you, and the guns deal so much damage that you need to consider taking another deal for bulletproof skin, so now they're a nonthreat. Then the game ups the ante again and has ghouls pop out of the ground that you can barely hit due to their smoke-like bodies, so you need to consider making another deal to get an evil aura that pushes them away or destroys them outright, but then the game ups the ante again and throws bonified demons at you with powers similar to yours, so you make another deal for awesome demon claws that you can use to cleave those guys in two, and etc and etc and so on and so forth. So the game is a giant contest of one-upsmanship of the game against the player, if that makes any sense.
Also, to reflect the character losing his humanity, the environment can start off very sane, perhaps even cheery at the very start, and as you take more deals, the architecture changes from benevolent to malevolent. Hallucinations become more frequent and powerful, and generally everything changes from happy, to hopeful, to dreary, to hopeless, to apocalyptic, and then to hellish, in a very gradual slide downward.
Also, perhaps just for fun, depending on what powers you have at what areas, it would be possible to take different routes through the hospital, so you could play through the game normally, then as you become more skilled you find that there's different ways to do things, or that the architecture in certain areas is very different if you manage to get to them without making alot of deals.