All upgrades add money.
When the zombie apocalypse comes, you must be ready to fight with the dead! In particular face to face! In this game you start to cut down walking with an ax, for which you take coins. Subsequently they can be purchased for improvement or replace the more powerful player. It is important that each zombie has a very large health scale - up to 999 points. And a swing with an ax makes one point of damage! Therefore, you have to get coins for upgrades (cost of the first is 30 gold) or the acquisition