In HPDD you have to balance your health with your mobility. The more health you got the harder it is to move around. On the other hand, if your health is low you can move fast as a bullet, but can easily die if you make a mistake. Luckily the same goes for the monsters around, you can transfer your health to them shooting health bullets that deplete from your own health to make them slower (and you faster). Then dash and slice them up to deal damage and take some health back.
The game goes with the theme "The more you have, the worse it is" and is designed to make you want to play just one more time to try to beat the game (As far as I know, no one but me has beaten it at the time of this writing).
But enough of this blabbering, here are the links:
Ludum Dare: https://ldjam.com/events/ludum-dare/40/high-protein-diet-dungeon (rate if you will)