It's hard to say. A good-looking and informative first post is essential, but beyond that it's kinda subjective. It depends on whether I think the game is worth showing off as a Game Dev "product", which I'm sure sounds entirely unreasonable as it's just my personal opinion, but I make the rules so there ;)
Oh, obviously the game actually needs to be in development, with clear signs that the developer is serious about continuing and completing it - strictly no ideas threads.