OzCthulu - the Outline

I've been working on the idea for an Aboriginal-Cthulu setting for quite some time. Originally I conceived of it using AD&D 1st edition rules, then later Microlite d20 and afterwards The Window (quite a nice little rules-lite system once you get past the overbearing elitism). I think Labyrinth Lord will be a nice fit, because it strikes the right balance between simplicity (which AD&D 1st edition doesn't have) and structure (which is where The Window especially is lacking). I haven't decided whether to make it classless or not as yet; we'll see where my instincts lead me.

What do I want to get out of the setting? Here's a smattering of what I've been thinking of including at various times:

• Ancient Australian megafauna. That's non-negotiable. Giant Wombats! Marsupial Lions! Giant Tasmanian Devils! Best of all: A bird called Bullockomis Planei, the 'Demon Duck of Doom'.
• Great Old Ones and Outer Gods. This is going to be a game which is set in the dawn of human time, analogous to our world 60,000 years ago, and is supposed to catalogue mankind's first conscious encounters with the beings of the Cthulu mythos.
• The Dreamtime. A parallel existence, 'more real than reality', whose happenings have mysterious and powerful effects in the 'real world'. Characters who can have contact with the Dreamtime and the beings that live there, and encounters and adventures in which the player characters have to enter it.
  
• Dungeon delving! Because it wouldn't be D&D otherwise. The setting is impossibly ancient, but the world is more ancient still - with endless cave systems as old as time itself. What lives inside them? What forgotten creatures, present at the beginning of creation, still lurk in the depths?
  
• The Bunyip.
• Spirits of place, which have to be pacified and placated before they allow you to pass through their territory.
• Yaramayahoo - giant tree frog vampires which swallow children, regurgitating them as yaramayahoo themselves.
  
• Executioner-assassins who can pursue their quarry with relentless accuracy and possess the power to kill them with a touch.
  

I've started getting excited about it again, writing those ideas out. At the moment things are so amorphous that it's difficult to get a fix exactly on what I want, but everything that I have, I like.