I think it also depends on your skill level if it is a good project to tackle now.
Guess you could write a little about where you stand.
Also what are your goals? Do you want the game to make money at some point?
If you do what you have written you will have a world ... but will it be a game?
I'd create a design document that gives an idea of what playing the game would feel like.
How does the player interact with the world exactly? I wouldn't start until I have more of a plan in place.