My personal view, is that it would be smart to use a control that is commonly available to assistive technology:
PC = Left-click and/or SPACE BAR..... One single input to start, play, and restart the game. No mouse pointer movement, and no extra keys needed.
iOS/Android Touch = A large static target area (ideally most if not all of the screen). To start, play, and restart the game.
Console = A or CROSS button, enough to start, play, and restart the game.