The ability to feasibly obtain treasures without coins.
Hunting at this low level means you cannot control enough oasis and cities to provide for a large army, so the provision in the game that supposedly provides nuggets does not even account for low-level players who need that nugget to level up.
I supposed every developer needs to make money somehow, and the coin system provides for that (because spending money will make you better in-game, the amount spent is proportional to how good you are) but forcing players to spend money just to level up in such an early phase of the game is just greedy.
I hope something is in the works - a quest system that rewards a nugget is probably the best thing I can think of right now.