The home screen is the screen that's found when you enter the game! While on the page exiting and adventurous Music plays! It has a few things (it basically works like the launcher of minecraft) like settings, the changelog, the server and much more! But, without it you wouldn't be able to play! The first time mope.io came out, it only offered to type in your name and show the changelog!
There is no more game mode selections above your name since Feb 18th.