Woooow, cool game!, nice music, the idea of a chess board in the down scene, the idea of energetic balls to translate to another worlds, that so look fine, I think, you need a start UI where you show the title , the goal and the mechanics of the game. May be you could enrich your UI with a brief story about the game and your main character, and could add buttons to play the game, settings like the sound volume and the credits screen where you can show the name of the asset creators in your game. With this game you shurely will win the jam.