So, the guy behind the bfxr tool has made something really cool: http://www.puzzlescript.net/

It's a game engine and custom programming language (which must use predicate logic) to build the rules for a video game. I think that is a rather neat concept! Data representation is a really big concern in anything AI related and using a sound representational system like predicate logic, is a very neat way to do something like this.

Check out the how-to here to get your mind shattered: http://www.puzzlescript.net/documentation/rules101.html

I can't get it to work. I have the latest version of Firefox, I have NoScript disabled (i.e. allowing scripts globally), and none of the buttons in the editor work :/

Can't load games, can't run anything. The gallery looks really neat, though.

It all seems to work for me. Have you tried playing any of the games?

I think the whole project from a data perspective is the neatest darned thing I've ever seen and I don't know why game programming can't be something very similar to it. I know the programming language the author made takes a lot to wrap your head around but it sure is elegant. The guy has coded a way to push another block using one line of his code. A rules based system that determines input and output. Although it's very clever, the game engine still does a lot of work like know which key you pressed and in what direction. But at least the action and reactions are undefined, which is totally and remarkably awesome that he was able to decouple them so well.

It's exactly like using functional logic to construct a game, because it basically is.