This game has been meandering around quite a bit.
It has actually given me some time to thinking about where this game is going.
First of all, I'm still very keen on the spherical world. The idea is that each player will more or less own their planet and be able to visit others for various different reasons. Being a spherical world, it creates a natural limit on how much can be built out. In a sense you can complete a world and not be forever extending in different directions. There are different size worlds, some small, some big. The other thing is that the height map of each planet is limited as the hexagons get bigger as they get further away from the core. However I'm thinking that one way to deal with this is to have layers, each separated by some sort of air gap. One layer could be the ground, another the cloud layer (think floating islands) and yet another some subterranean cave system.
I like tactical games as well, so the game play focus is on tactical game play. So, the story will be fairly limited. An it will also mean a third person camera.
I like multiplayer games. The multiplayer aspect will be something like you can visit another player while the other player is off line. From a game play perspective, this could mean a lot of auto defense.