There have been several games sitting on our downloads list that haven't been accepted for quite a period of time - for some reason or another. The reasons are usually based on the lack of screenshots, description, or incorrect links, and we usually inform the user by posting a comment about it on the description of the game page.
If your game was submitted a while ago and it hasn't been accepted yet, there is an extremely good chance that the game hasn't met the criteria mentioned above. So it's a good idea to check your submitted game. If you don't know how to do that, click on User Admin in the left hand column, and then look for your game on the list of your submitted games. Take a peek using View and if there is a comment there from an admin, amend the download accordingly.
If, after a period of time, nothing has been done with the download, it is quite likely to get deleted in order to avoid clogging up the list.
This is something for you to bear in mind when submitting a download; check it before submitting to avoid potential problems!