First of all, thanks for being open and looking for ways to improve the system.
Second, this are my suggestions, I’ve been discussing these quite a lot in the GMTK Discord.
The host should pick a % of number of ratings, the games below that % should get a proportionally lower score based on that % but not affect those above it (Basically the system as it is now but without boosting people whose games are popular so that everyone is on even footing instead of being a popularity contest and giving the host the power to set that % because the median is not enough for larger Jams.)
There should be a way to browse games the top rated games without ranking them, so they cant be targeted easily Like showing the 10% most rated games but sorted in random order. (This makes good games float up without putting a target on people who are really popular.)
Don’t show others the ratings and comments your game has. (This makes bombing someone that has lots of ratings harder and it gets rid of the popularity bias that makes people be more critical towards those games.)
Only people who submitted a game can rate and only after leaving a comment. (This puts the focus on giving good feedback and fair ratings, getting rid of friends and family voters that boost games.)
Those are my thoughts, I'll add more if I can come up with other suggestions.