you should release more free worlds imo, I have won first place in all in the first 3 however to pay 7500 for a new one is unrealistic and they only way to do that is by paying the money, The game has elastic demand imo so you would be better with more free things and ads rather than paying
great game, high potential, keep at it :) you should make it a bit harder though and possible more interactive, after upgrading recources for 15, left computer off for a day, bought loads of building, another day off, all research bought and now i feel there is nothing left to do
bought the lava stuff for 50k, killed over 100 golems just to get 60 pieces of dust, got the armour, picked it up, invetory was full so it dissappeared, done with this game anyway