Re the creatures.xml: If I add a new creature, where do I add it? Assume it's needed for the Corp HQ and may or may not be guaranteed at a location in the place.
Currently you can't add new creatures in the creatures.xml file yet, you can only edit and mod existing ones... at least I think that's how it works. The reason is there's SOOO many places in the source code where various creatures are hardcoded in, and I highly doubt Carlos Gustavos un-hardcoded ALL of them, he just un-harcoded enough of them to make the existing creatures moddable. I'm not 100% sure of this, but I'm pretty sure. For instance, one thing that I think is hardcoded is the lists of which creatures you encounter at which locations, and the probabilities of them. The encounter probabilities actually differ depending on factors such as whether folks at the site are alarmed or not, whether or not there's a Conservative response such as the police showing up, whether or not the site has high security, which area of the site you are in, etc. For instance, the downtown apartments get Guard Dogs when there is high security, but only in the hallways, not in the apartments themselves. Just one of many many things that are hardcoded in the source code.
Technically though I think you CAN add new creatures to the creatures.xml file. The only problem is, you'll never encounter any of the ones you add. So even though the game probably will load the whole XML file including any new creatures you add, the fact that none of the creatures are spawned anywhere, well that will be a problem, make it impossible for you to encounter any of the creatures you try adding.
Anyway, we'll treat this as a feature request, to request the ability to modify which creatures spawn at each location in an XML file, so that people can mod that part of the game too. Not sure whether it belongs in the creatures.xml file or a different one, like an XML file about the locations, or one specifically just about which creatures spawn at which locations. I would lean towards having it in a different file from creatures.xml, because this would make it easier to preserve the logic of the source code (where different creatures have different probabilities). Having it in the creatures.xml file WOULD work if the spawning logic were much much simpler, then each creature could have a list of possible spawn locations. But because of the probabilities and because of different statuses for a location like security level (low security or high security) and Conservative alarm/response level and whether or not you're in an area where the public isn't allowed and a disguise is needed, well these complicate things, and so the spawn logic is done separately for each location, rather than for each creature, making it most logical to put it in an XML file about the locations. And it would probably make the most sense to have a separate file in the art directory entirely devoted to the purpose of spawn locations, because it is complicated enough to belong in its own separate XML file rather than one of the existing ones.