Die at the same time you kill a Boss. This is best
done when fighting Revenent Prime. Get him down to very low health
and wait until he starts to destroy the building you are standing
on, then let him have it. As you fall to your death the game will
continue to show a short FMV sequence, and you will start the
next level with 0 health. Enemies will not be able to kill you,
but you can still die if you fall off the level. Note: The health
warning will constantly sound.