To start a new game account on Steam, open Gems of War. Whilst the game is loading, press and hold shift + 6 until the text "Are you sure you want to delete your account from this device?" appears. Select Yes.
Deleting your account or game will only delete the game that is stored on your computer. Your account will stil remain on our servers.
Note: Note down your password before you delete your old game, otherwise, if you want to play your old account you'll need to contact support to recover your password. You can verify your account here (each account requires a seperate email to link to).