I'm going to act for a moment as if I've got a captive audience for my obsessive ramblings.

One of the biggest challenges for making that game is content: first, what it could be about, in general. I sort of understand that the people that would be interested in something like that would want buying groceries, booking a flight, renting a room... Things that I don't care about at all. I'm actually a fan of medieval history, or at least folklore... But even if I assume that as acceptable subjects, I actually need something more specific - that comes after "Ich heiße Wilhelm". And I've had a lot of difficulty with that. And not surprisingly - game writing seems to be one of the hardest areas, at least to do right.

But the most expensive area, I believe, is graphics (in terms of time as well as money, for those who have it). Or it could be extremely cheap - if it were an entirely text-based game. Unfortunately I don't find text-based games interesting... But then if there were any graphics, it would make sense that almost every word or concept have a graphic representation. You don't mention "Hund" without showing it and providing appropriate sounds... So there, any way I look at it, it quickly gets out of hand, at least at the limits of time, money, and sanity that I currently possess.