All those points aside, there is nothing here to entice us to work for you for free. Granted the loop you want isn't even a minute long and in a way that isn't asking for all that much. Yet, at the same time there is no information about the game. No game play videos, no pictures, not even a paragraph of text to explain what the game is about. I'm sorry, but as artists we need some kind of setting or guidelines if you want to inspire anything good out of us. Also, upbeat chip tune? What kind of upbeat chip tune? What chip set are you looking to imitate? What style of music is your upbeat chip tune inspired by? For me, it's not so much that I am offended by being asked to create music for free when it's less than a minute long. I am turned off by how vague everything in your post is. The worst part is, you say you'll give us credit but you're not even sure how you'll do it? How about putting us in the credits?
If you want anyone to respond positively to you next time please at least tell us a bit more about your game. Inspire us with something, otherwise even if you do get something you'll have no idea if it will be what you want and that just creates further problems.
Please man, I'm trying to help you. Maybe your game is awesome, but if you give us nothing to go on we'll never know.