Click anywhere on the screen to show the hints. Press 'h' to hide hints.
Spacebar opens/closes the hit box. Use the number and arrow keys to enter data. Press enter to hit the ball.
Escape brings up the pause menu. Use the arrow keys to navigate and enter to select/change. Escape moves backward one screen. You can change the game mode from this menu.
Press 's' to show/hide your scorecard.