In some forms of Vampire lore, a vampire's strengths are determined by their satiation. In some cases, the more blood-starved, the stronger the vampire. Within Bloodlet, you will attempt to make your way through each level, only able to move on when you reach peak performance at a health of one. When every move you make costs one health, and and various objects scattered about that can impact your health, you'll have to think carefully about the path you take.