For the judging there is no visuals, but there is sound design and gameplay. So does this mean if someone makes an ugly game, but it has good gameplay, and sound they might win?
Each jam is different. In this one we want to see a game that plays well, sounds good and fits the themes. If they use ugly defaults, that's fine. If someone puts extra work in making it look good it will most certainly get a higher score overall just because it will feel better to play a more customized game.