Health drops like Diablo III and many other RPGs. Gain health as you wade through the armies of the night! Beyond just health, Orbs 'n' Stuff adds a variety of other orbs that can spawn on kill. All orbs are fully configurable in-game.
HP Orb
Your basic health-boost orb. Gain back some health when you pick it up! Orbs drop more frequently when you are at low health (by default), helping you stay in the fight.
XP Orb
Much like it's vanilla brethren, this orb grants you an XP boost on pickup. Its chance of dropping is increased when you kill mobs you haven't killed many times before.
Status Effect Orb
Unlocked once you've entered the Nether, these orbs grant positive status effects on pickup, with a rare chance to provide 2 statuses in one go! These orbs drop more frequently the more statuses the killed mob had.
Boss Orb (Orb of Accomplishment)
Dropped on first kill of a boss, these resplendent orbs grant you an Orb of Accomplishment on pickup. Use that orb (right click) to choose between one of three randomly chosen permanent stat boosts!