Tangata Manu development

My initial concept for the Tangata Manu game was really simple. You are trying to move your figures up a cliff while the other players are trying to knock your figures off the cliff with large boulders. The winner would be the player that moves the highest number of his figures successfully up the cliff. The Tangata Manu ritual seemed like a perfect fit.

The Tangata manu (the bird-man), is the winner of a traditional competition of the Easter Island people. The ritual involved swimming over to a small island and stealing some bird eggs and then swimming back and climbing up the cliff without breaking the egg.

This game would be somewhat based on that ritual. The game board represents the cliff. My initial design has 6 tiles that could be placed at random so the board would be slightly different each time. Each player has a number of figures (possibly 12) that he will move up the cliff.

My first thought on card based movement was too slow. I'll make the game board a little shorter and try a card based movement similar to the game Castle Merchants where you have to play a trail card and place the trail and then play a similar card for any of your figures you wish to move along that trail. Originally the rock movement was solely at the discretion of the player but I'm now playing with a randomly drawn rock movement card that is drawn on every turn and the player has the choice of which rock to move where...