@not_davido makes some good points: here are some more.
Don't be afraid
Your first game may be broken, not what you intended and will have a lot of problems, but everyone must experience this in order to improve. Submit it anyway. It's good to make other people feel comfortable with posting unfinished WIP games.
Check out GBStudio
GBStudio has drag and drop code and an extensive amount of documentation and third party tutorials. It can also export ROM games to be played on original hardware.
Reduce your scope
Everyone wants to make the next big MMO game, but realistically even games like pong and space invaders can be a bit of a stretch. Think of an idea and cut it down and then cut it down some more. Even making a short interactive title screen is a valid entry.
Your game doesn't even have to be playable
You only have to convey your idea for the game. You can even make a series of screenshots or a music album and submit that.
Submit something at least 24 hours before the deadline
You never know when your code might go wrong or not render properly. Submit something, anything, before the deadline and then update with another file later.
Team up with others
Other people may be able to fill out the gaps in your knowledge. Peers and mentors are valuable for getting started in game development.