Use the mouse or the keyboard to input words. Shortcut keys are: Enter = Submit, Space bar = Shuffle, Backspace = Remove letter.
Click a letter on the input area to remove it and all following letters. (Given letter can't be removed.)
Note: you can retry as many times as you want after losing, but if you make it through the entire game without a single retry, your final score will be DOUBLED! (Quitting the game and continuing later counts as a retry.)