Pretty much like a minecraft world in the shape of a disk cos of all of the different areas (jungle, dead lands, swamp ect.) If you need more info just read the first half of Summoner The Battlemage. The blurb reads "Fletcher and his friends are fighting for survival in the ether. Hunted by deadly Wyvern-riding shamans and wild demons that inhabit the alien jungles, they must race against time to find a way back to Hominum before their antidote to the ethers poison runs out".
And also the game that you are creating sounds very interesting.