The Down Button is not bad, it has no affect on the votes you need and the game disappears from the voters list. I think Valve is already doing it better than Apple at least, if you like to publish on the ITunes store, you need to pay 99$ every year. For steam, it is a one-time fee.
Anyhow, I have submitted a game (was developed over 10 years, with nearly monthy releases with additions and fixes) before the fee came up and took it down again, because I was really annoyed by all the flaming on the graphics (yes, the game does not look great but there are much worse games on Steam).
If you don't work on a 1:1 clone of Battlefield, don't waste your time on Greenlight.