If you download a resource, be it art or plugin, please thank the creator for their time. We are all guilty sometimes of just grabbing something without commenting. Now is the time to go through your credit list and visit the threads/site where you got the resource from and leave a heartfelt thank you!
SIGH its so hard to convince my friend that making a game for fun and making one to sell takes different planning. I don't care about weird bothersome ways of doing things in a game made for fun, but when you are planning to market it, there is some stuff that you just have to streamline or cut out.