I think a lot of great game play mechanics can be developed in a game jam. This type of underling work can be more then a enough to catapult a game into a paid game. Honesty, with enough continued effort many games could make the transition. Selfish plug incoming, here is what I have submitted to the jam...
Please leave feedback as this is my first Jam and my most polished game so far. https://docdoc116.itch.io/afterlife-keys