although the game could be interesting there are two black spots that make me say it's not really worth it:
1) planet coins. This is the game main value. Without it, half of the game will be hard to impossible to access, be it items, expeditions, and other stuff. You only get 1 every 5 levels, so to buy an expedition, say, it will take a looooooong time.. far to long, imho.
2) facebook: without a FB account, you can't create an army. Well, i don't have one, and i certainly won't do a FB account just for this.. so i'm out of the army thing as well. But armies are used in some PVP, so there it goes another slice of the game. In the end, if you don't want to spend money or use FB, you can't really enjoy this game to its full.