A progression from orderly idyllic light hearted exploration downward into dangerous and consecutively more harrowing escapes/problems, culminating with a cataclysm and rebirth. Like Akira but with Mice or something.
Set it human suburbia, with PCs as cute little animals, menaced by one or more predators. As the game/campaign progresses, more playable races 'unlock' depending upon making friends and doing favors, whereas negative actions add to predators list. Faeries and magic as an optional plug-in, and the alternating corrupting and purifying effects of the humans decided upon by group consent. Does it look like a dry summer? Is there a hurricane? Is Mr McGregor having a hard time with his wife and so disposed to be cruel, or is he playing too much WoW and awaiting DnD 5e so the garden is unguarded or going to seed?
Rules light, 2d6 best-of for resolutions
Birds, bees, mice, rats, praying mantises, butterflies as PCs
snakes, dogs, foxes, coyotes, etc. for antagonists
Pixies, Nimh Rats, Goblins, Faeries, for the optional plug ins.
Maybe each turn two players nominated to act out human aspects of the story. Truck broke down in the field? It's an obstacle for the plow so Ms Brisby can move the kids across the way with a rattlesnake in pursuit. Why did the truck break down? The faeries sabotaged the distributor after Ms Brisby got them a set of keys from McGregor's house so they can doppelgang the new baby...
Anyway, just a placeholder since I can't sleep. What are the effects of the relentless hacking back of the wilderness upon the characters of the characters?