I would say maybe a lot of people are afraid of making platformer games on a game jam because of how many there usually are, but this time I only found a few so yeah I was surprised, also if you want to make a platformer game there is market but you have to make your game stand out because a lot of people (this is me talking from personal experience) are tired of the basic platformer mechanics, but I would say if you make a good game there will always be people willing to play it :D
-Marco