I think this would make a EPIC MMO game. Keep it like it is, but just remove TNT and Fire (except torches for lights). Then each player starts out on own little island, you expand from there. Take over enemies islands but bridge/tunnel/etc. Be like king of the hill. Other plays could not do anything to your island, but add to it. So that way you don't just see massive grieving of other peoples stuff. Like if you spend 30 hours building a tower. If someone took of island they could just add other things TO that structure, or new stuff to area.
I don't know, so many possibilities if it went MMO. They guy would be richer than he is now. You don't need to change graphics, or anything, all about gameplay with this game.