An idea - during game creation, instad of typing the name of the opponent, you could write an email address, which would send an email invitiation (to an existing or especially to a new player), taking the invited person directly to sign up form and then directly to the game. Not the highest priority at the moment, but it would make it easier to invite more people into the game.
Good idea, this has been on my list for some time. Although the implementation I had in mind would be to have a separate box in the Lobby, below “New Game” section, that would create a game on some beginner friendly map (potentially we could have a map where the new player has a small advantage to compensate for their lack of experience).