***game mechanics spoiler***
Just a little hint before you attempt this, as it gets tricky later on, beat normal first, you get all your weapons all your upgrades and all your dresses for the next playthrough. Sweet deal eh? it gets better. The dresses you've unlocked now have bonus abilities, for example, the default dress now heals you when you shrink, hardly a bonus to sneeze at! Other than that this plays just like every other difficulty, you just take more damage. Have fun!