How to change new game in same email?

You can start a new game at any time, just go to the settings menu and then 'Account' and 'Start a new game'. You will start a new game in the most recent state.

You can bind your game to a different email address or you can use the same one as before but change the capitalization. i.e. instead of [email protected] use [email protected]. You should still get the confirmation email sent to you but the game will treat it as 2 different log ins.