Does any button related to metadata (such as undo, restart and go to the main menu) counts as a button ?
Pretty sure buttons like that don't really count, they're talking about keyboard keys, etc. But bonus points if you do!
Those don't count but you do get bonus rep and bragging points if you can figure out a way to handle them with one button :)
How about buttons that makes those actions ?
As i said, they're ok. The 1-button rule applies only to gameplay. Using one button to navigate the menus is just an extra optional challenge.
