Very interesting idea Bogie, I'm very curious to see how you will approach this.
I remember the first time I ever played Mancala was inside of a computer game (Quest for Glory 3). I don't know if it is a good idea, but seeing as Mancala is African in origin, maybe you could work in some sort of African-Fantasy type style.
Then again, a complete departure from the game's roots into some strange alternate setting seems entirely appropriate also. Like I said, I'm very interested to see how you will approach this and eager to see the end product.