I'm pretty sure this has been reported but just wanted to put my 2 cents in!
First bug i ran into was the polearms was not celculated right (says 10 polearms for 1 coin, but actually charging me for 10 coins which im assuming is correct cost just did wierdly hehe) http://prntscr.com/e6rhbf
Second after you make more then 200 coins the game starts running really choppy using alot of CPU and its because of the coins colliding with each other rapidly
keep up the great work! i made sure to donate (not much but its all i had :/)