Having a high replay value would be definitely a booster to success. The most popular Flash-games aren't known for their complexity or lenghty chapters. Only problem is, we're making a horror game. Horror games in general (think about Silent Hill for example) don't have a high replay value. Hence, often they're not even fun to play at all! You watch a movie or play the game to learn the story, wet your pants, and then put the box back in Hell. All in all, not the typical recipe for making the next Angry Birds. The audience will be relative small. Then again, there aren't much truly scary horror games out there, and Amnesia/Penumbra, being underdog Indie games, have become standards when people speak about scary games.
Horror is all about the experience, and -unless you go for scripted shockers-, it's extremely hard to suck someone in a "uncomfortable-mood" within just a few minutes, or having a minimum amount of environment. That's why I figured the play-time should at least be around 15 minutes (it could be 45 minutes if the game isn't too easy, putting the player on a linear path to the finish-marker).
More would be even better, and chopping the game into Episodes as you say was one of the initial plans. I still think we should head that way, but the truth is that creating content for even a single episide (think about ~2 hours gameplay), would take too long. At least, in the current state of our team. I wish it was different, but there are just a few 3D artists that put their scarse time almost randomly on the project. That's not a solid basis for promising (and asking money) for a complete Episode of course.
That sucks, but I can't force people into making things without giving some in return ($ & satisfying results). Looking for more artists is an obvious first step, and we'll do that again as soon as the next movie is finished (should be within some months). But since the quality bar is quite high for T22 -probably a bit too high- finding good artists with time and willing to help for free, is extremely hard. And so is keeping artists. They too want concrete goals, short-term results, progress. Working on a far-away Episode isn't motivating enough for most.
This fund-raising plan + playable demo is an attempt to transform the project into more serious proportions. Releasing a not-too-big playable demo is a clear goal for (new joining) artists. Giving small rewards in return for their work, should be a motivator. It's certainly not a month salary, but if you can earn ~125$ extra per month with your hobby, why not? The budget really is to keep the artists going, making realization of the goal a lot more realistic, on a reasonable tempo. I always hoped money wouldn't be needed, that sheer enthusiasm would be enough for fuel. But as explained above, it unfortunately isn't. Not if development gets too big and lengthy.
If it all works out, meaning we achieve a playable demo within reasonable time, that is liked by the audience, a bigger next step should certainly be possible. But to reach that phase, the project simply needs a booster. Money would be the glue to keep artists sticking on the project. So the budget is purely for making that demo only, which is why it can be kept low initially. But if people are really willing to donate even that relative low amount... We'll need our charms :)
Sorry for the looong response hehe
Not sure of credibility but even there are people giving this service but also afaik you have advantage of being EU Citizen ie chance of having a company at UK. ( I am non-EU enough not to know details, this may be quite wrong 
