You wrote on your page that this is the first game you have ever tried to make. It does not look like one. The cover is a painted book with the traveller small against the mountain and the town burning gold in the valley, the title line is The legend outlived the dragon, and the two buttons are Open the first page and Ending Gallery. Someone who has shipped five games would be happy with that entrance.
One easy win, measured so you can check it yourself. Your itch frame is 1280x720, and the book inside it is 544 pixels wide, sitting in the middle. So about 57 percent of the window a visitor sees is black margin on either side of your art. Nothing is broken, it just makes the book smaller than it needs to be.
The fix is on your game edit page rather than in the game: set the embed width and height to something close to the book itself, around 560x700. Same game, same code, and your cover suddenly fills the space it was painted for. It is the cheapest improvement available to you before the voting starts.
Having an Ending Gallery and a Chinese toggle on the first screen of a first project is also more than most of us manage.
Disclosure: automated headless pass at 1280x900, so I read the cover rather than the ballad. Coming back to open the first page properly.
Ours is TORCH IT! if you want to swap.