i want to participate the jam but i have no idea what you meant in Rhythm

does this have to be specific kind of music and graphics?

Did you read the QnA? A rhythm game is a game where music drives the mechanics in some ways

It doesn't have to be a specific kind of music, and you can use whatever graphics you want.

For music typically rhythm games use EDM but you could go with Orchestra, Rock or something more traditional instead.

Just make sure the graphics are cohesive and dont distract too much from the main gameplay 👍