A Symmetriad
The most powerful image which stuck with me from Stanislaw Lem's Solaris (which I read in Joanna Kilmartin and Steve Cox's translation) was that of the "symmetriad". Solaris is an extraterrestrial planet covered by what is apparently an intelligent, yet entirely alien, ocean. Many pages are spent discussing the phenomena which the ocean exhibits, and the frustration of earthly science to make any sort of sense of it. Here is an evocative part of the evolution of a symmetriad (pp. 127-128):
The symmetriad now begins to display its most exotic characteristic–the property of 'illustrating,' sometimes contradicting, various laws of physics. … The interior of the symmetriad becomes a factory for the production of 'monumental machines,' as these constructs are sometimes called, although they resemble no machine which it is within the power of mankind to build: the designation is applied because all this activity has finite ends, and is therefore in some sense 'mechanical.' …
It would be only natural, clearly, to suppose that the symmetriad is a 'computer' of the living ocean, performing calculations for a purpose that we are not able to grasp. … The hypothesis was a tempting one, but it proved impossible to sustain the concept that the living ocean examined problems of matter, the cosmos and existence through the medium of titanic eruptions, in which every particle had an indispensable function as a controlled element in an analytical system of infinite purity.
Quickly as the book dismisses the concept, I read a lot into it. The way in which the symmetriad is accompanied by "local changes in gravitation", among other oddities, suggest that through this immensely complicated structure, the ocean is able to manifest physical effects far beyond the symmetriad itself. The "ghosts" which are a major aspect of the story seem to be generated in this way, and the same holds for the impossible orbit that the planet keeps around its binary star. I would like to consider the idea of a "physical" computer in a game, which embodies some aspect of the rules.
Recall that my initial idea was to have the game system written in the same language which the player uses to interact with it. At the time I was thinking of a textual programming language, likely something along the lines of Forth for the benefit of its minimal syntax. But consider if the game has the typical adventure game interface, such as in an early top-down Zelda. The interface there is walking about, which lets the player indicate positions and paths. The game world provides other objects and enemies that also run their own computations according to some program. Now imagine that these programs are represented by physical systems elsewhere in the game world. This could take various forms: it might be somewhere near or distant in the same "physical" world, it may be on some higher plane, or we might have a tower wherein Floor 1 contains mechanisms used on Floor 2 and so on up.
The player might be able to manipulate these physical computers to modify the behavior of various enemies or game systems. He might further be able to create his own programs by placing objects, or moving through mazes, which would manifest as a physical effect elsewhere in the world according to the same system. This somewhat models real world computer systems, where computational devices are built up of intricately arranged physical objects. Decoupling these in space, and allowing physical manifestation, is more of a magical effect.
Unfortunately, as compelling as I find this idea, I have yet to come up with any practical examples.