Collecting Red Health Potions is optional in any%, and grant a boost to your Max HP. Collecting 40 out of the 77 in the game also lets you unlock the Ballista weapon before the final boss rush through Primordial Abyss.

Deadwell - 6 Forest Path - 2 Ravenfen - 4 Greenslit - 9 Trollhole - 3 Nokkpond - 6 Trilobite Tomb - 1 Fallcrush - 6 Nokkpond Underwater - 3 Sourwood - 6 Darkthroat - 3 Marebog - 3 Granite Gash - 8 Hypothermia Waste - 2 Haunted Glaicer - 5 Drowned Veins - 9 Primordial Abyss - 1