For a variety of reasons, I prefer this site to other similar distribution platforms, but I think we all know there is another site that is beating the pants off of this one when it comes to game jams. Having run two game jams on this site, I have a few suggestions to bring itch.io up to the best of the best when it comes to game jamming. Some of these are things the other site already has that this one is sorely lacking, and others of these ideas are my own ideas from my experience running jams.
1. Custom pages - Be able to add pages to the jam that have separate tabs across the top. Right now the jams are all on one page and if you have a lot of info, the description gets quite long-winded. Jam organizers should be able to add other pages to categorize the content.
2. Awards - Right now there is a rating system that ranks games by voting criteria, but you can't single out games for specific awards. Example of awards might be a "judges choice" award for each of the judges or "smallest file size" award or any number of things a game could be recognized for that makes no sense to be a judging criteria.
3. Weighted Criteria - The jam organizer can weight the criteria as to how much they will contribute to the overall ranking. If a jam is very story-focused, the organizer will want to weight the "story" and "characters" criteria higher than "graphics" and "sound." This can be done by having a multiplier for each criteria that defaults to 1.
4. Multiple Voting Systems - Each game could receive a community vote and ALSO a vote by the judges that are counted separately from each other. Both systems have their good and bad points, so why not be able to have both.
5. Manuel Ranking - An additional ranking system is added which can be enabled and then ranks are entered manually by the jam organizer. The organizer gives each game a rank by hand based on either his sole discretion or any other way of judging that takes place off the site such as in-person discussion with the panel of judges.
6. Back Bin - This is an area in which games are put that are disqualified from the jam because they did not follow the rules. Many jam organizers, including myself, don't want to wantonly toss games out of the jam entirely if they failed to follow one or more rules, but they should be excluded from the primary ranking system. This is important because people who come to the jam after it's over to play the games, are going to lose interest pretty fast if they keep running across games that didn't follow the rules. After all, they chose to play games in this jam for a reason, presumably because they are interested in the theme or rules. They don't want to find games in there that didn't follow them. On the other hand, people did work hard on those games, and it doesn't seem completely in the spirit of a game jam to just toss them out.
Thanks for reading my suggestions.