Sorry to be that guy, but what a terribly ill-posed question. You really have to not "get" NNs to ask something like this. Here are the problems with it:
1. DF does not have any "score". To train an NN, you need to show it inputs and matched correct outputs, then it (supposedly) generalizes the output. What's your training set?
2. NNs, by their nature, function by trying many solutions over and over. How long does a non-trivial game of DF take? Yeah, that, times hundreds, maybe thousands (because the problem is so bad, maybe millions!).
3. Good luck when the NN inevitable gets stuck in the thousands of local minima that must certainly exist.
I just wanted to point out that you're confusing GA with NN. The two techniques are often, but not always combined, in order to create a
sort of learning system, but be assured that the two techniques are entirely different from each other.
GA needs a "score". GA requires hundreds, if not thousands, if not millions of iterations. GA usually, but not always requires stable scenarios. GA frequently gets stuck in local maxima, but can be kicked out of it by running multiple GA at once and cross breeding them occasionally.
NN has none of those problems, but has its own set of problems. For example, the need for a finite and preferably VERY LIMITED (like, a number you can count on your fingers) number of inputs / outputs. So you couldn't really hook the NN
directly into DF, which has an insane number of potential inputs-- you could say "each tile", but you'd also need inputs for each possible item/creature in a tile. But forget that, you can't really do it.
So what you need is a rule based system that handles what are often called "tactics"... analyzing big-picture stuff, like your overall economy (the "wealth", "food", and "booze" numeric displays could be good inputs, for instance), number of invaders on the map (not their position, probably not even their type, although you could split off titans and demons I suppose) number of living/dead dwarves, that sort of thing, and then use the NN to output a STRATEGY. Not tactics, but overall goals. For instance, if your booze is low, and there are a moderate number of goblins on the map, a NN could be used to decide whether to focus on getting stills up now or to get weaponsmiths going.
The NN wouldn't say where to put anything, it wouldn't say how to do it, it would just suggest "Hey, maybe we aught to prioritize booze right now", or "Maybe we could stand to draft a few fellows." Then, a rule based system would work out how to actually IMPLEMENT the strategy proposed by the NN.
Of course, an NN could certainly do this, but what some other posters are pointing out, is that NNs are hardly NECESSARY to do this. You could have a much more simple IF/THEN chain that analyzes the same numbers and comes up with the same goals. The thing about NNs though, is that they're really good at "fuzzy" situations-- such as my example of being low on booze AND goblins are invading. Which do you focus on? What if your booze is at 5, you have 50 dwarves, but there's a demon rush flooding your fort? What if it's a hundred goblins instead of demons? How do you weight in your existing military?
Basically, the NN combines multiple inputs and melts them together in such a way that, if you train it right, it'll make "smart" decisions. You COULD do it with an IF/THEN chain (or a switch, or whatever) but the more factors to consider, the fuzzier the lines between good and bad decisions in somewhat different scenarios, the more an NN starts looking a lot simpler to implement than an IF/THEN chain.
And yet the IF/THEN chain is simpler to read and understand for human beings. And that's the temptation and draw for it, because you could look at your numbers and understand exactly what it means in terms of strategy weighting. Neurons are a little trickier to comprehend. But if you know what you're doing with them, I think this may actually be EXACTLY the right place to use it.
But don't focus all your attention on the NN. You DO need a good system for implementing the overall strategy as well. You need something to tell the game where to dig rooms and where to put the still and so on and so forth. The best implementation of this... or at least the quickest... might be to simply apply some cookie cutter designs.