Remove Display:
During play, press Up, Up, Down, Down, Left, Right, Left, then hold Back and press Y.

Restore Health:
During play, press Up, Up, Down, Down, Left, Right, Left, then hold Back and press Right.

Restore Time Dilation:
During play, press Up, Up, Down, Down, Left, Right, Left, then hold Back and press Up.

Thanks to Revolution reader james!