I think some discussion about the gameplay would be appropriate.
Esenthel, I don't know how far your plans go and how much time you are willing to spend on this, and it's your right not to tell us.
But there are some things I would like to point out, and I would like to know if anyone (dis)agrees and why.
First of all, what you have implemented now is a decent start, but how will it continue?
The main problem to me, is that you can do things too fast. You build blocks instantly, destroy them instantly and raise/lower the terrain as if it's no effort at all. It's a style, I admit, and it's good for people wanting to go creative, but it's dangerous for gameplay.
Mainly, it turns the game into mindless repetitive actions.
Secondly, it lowers the "reward" you get, or in other words: How challenging the game is. Less challenge = less fun.
If you want to focus on players vs world, there should be clear roles. Someone is a builder, a trader, a fighter, a digger, ..
There should be a skill-tree which does not enable you to specialize in all these roles, but makes you pick one or a few.
Suppose you want to go for PvP as well, the siege becomes an important factor. Removing blocks instantly (or nearly-instantly like in minecraft) is a huge bummer when you see someone break through your massive Chinese wall in less then a minute.
These are my thoughts so far. It's not much to go by, but it's late and I felt like asking anyway.
What are your plans for future gameplay?
On topic, I can really recommend gameplay-enhancing books such as "A theory of fun - by Raph Koster".
Not that I don't have faith in you, but I learned a whole lot from those books.
Fun, challenge, risk vs reward, etc. All very interesting if you want to make a game.