You probably already know this, but you should add a collision or a limit to keep the player from going off the screen. You could divide the background into two parts: a static sun or moon, and the rest of the current repeating background. A tip, It's not necessary to place the player in the center of the screen; you could lower the ground and put all the UI at the top with a more visible aesthetic. Besides that, this type of game has many mechanics to explore and combine. Good job, Keep going!!