I played it a bit more now, one thing that bothered me was the bow weapon. Before the bow you get the hammer, and I was able to attack much faster with the hammer and get a nice amount of money. Then you spend a few thousand coins on the next weapon, and you get the bow which shoots really slow in comparison. So I basically went backwards with the amount of money I was getting.
I'd recommend either making the bow shoot at least as fast as the hammer attacks, or allowing you to switch between weapons so I can use the hammer for hitting the chest.