Looks like another game jam is coming around, and having made a game for the previous game jam I have some advice for participants.
You have to make sure your game idea is ridiculously simple and easy to make. Projects of any kind will take longer to complete than anticipated, not just games. Since we have 3 days to make a game, try thinking of something that can be made in one day. Believe me, no one ever complains about being finished too soon or having too much time. Developers too often set out to make their ideal game when they lack the means to do so. We have to be humble about this and concede that we can't make the game we really really want to. 28 teams participated last time, but only 10 games were made. If you can make any game at all, that alone will be a triumph. And while teams have succeeded in making platformers, I would recommend against that selection of genre.
Also, I think I made a mistake last time when deciding to try for a sponsorship instead of going the ad route. I site-locked the game to Newgrounds so that I'd still be able to sell it eventually. I was able to get a sponsorship for my game Pactime so I found myself under the impression that it's easy for any game to get sponsored, but this is not the case. Games made for game jams are made so quickly that it's probably better to go with ads than to try for a sponsorship. I doubt many of you will even consider sponsorships anyway but I just thought I'd throw that out there.
The game we made last time is called Strange Thoughts. We had to put symbols around the title because it was already taken by an animation.