I've given a bit more thought to the living terrain game, the playful, vengeful timeless spirit idea.
Current basic, model-free thinking on gameplay is a series of dice, each representing an aspect of the local landscape, say initially soil, plants and animals. These would sit together keeping score.
The two mid-range numbers, i.e. 6 and 7 on a D12, would represent an equilibrium, and be the scores face up at the beginning, while the higher numbers would represent higher activity, the lower numbers lower. Each player would have the ability to modify a die by a given amount each turn, according to kind of power wielded, as the spirit bends the realm to its will. A change on one die would cause a change in others, so an increase in plant activity would see an increase or decrease in animal activity.
If a die reached the maximum a whole new die would be added representing radical branching, for plants maybe carnivores, giant trees or flying pods. The creating player would decide the links between dice by placement, so flying pods would be set beside plants and animals, but not soil. If a die reached the minimum, it would be removed.
Goals could depend on the nature of a spirit - to bring all dice to equilibrium, eliminate another player's realm, create a new and so on. Modelled terrain could be used, with that still to think about, most obviously by having the dice correspond to the terrain during a wargame or roleplaying session for those polycosmic ripples I mentioned last time, with activity translating into changing difficulty or danger for troops or characters.
There's lots of tending to do yet, maybe some weeding or pruning, or even replanting._