10 levels. Words fall like bricks — finish typing each one on the Remington GAIL layout before it hits the ground. Miss 5 words and the game is over.
10 levels — words get longer and Shift-key letters get mixed in as you climb.
5 mistakes — miss (don't finish) 5 words across the whole run and it's game over.
Backspace works — fix a typo, just finish before the timer runs out.