First, I want to say you have a great team to complete this game. Very complete in tutorial and the UI Setting. And the art is nice draw. I like it. The background also nice for your game.
If you want some advice, I would like to offer two. First you can try to make your background makes Parallax which makes infinite scrolling background.(It can directly hence your game more) Second is to randomize your letters or speed up your moving to make the level more difficult. Or you can add more obstacles to Increase the difficulty.
But it still one good game and I want to play more in your games. (I am not sure why each time I will click twice on the "Fly button" and then start the game. But just one little bit issue. Does not matter)
Keep going. I like your game. (•̀ᴗ•́) و ̑̑