Items
Anklet

Good for one room only, the anklet allows Mike to jump up to two spaces instead of one. Apparently anklets turn your shirt orange as well?
Big Heart

These will increase Mike's total hearts by one and then refill all of your energy.
Coconut Milk

A sip from this jug restores Mike's hearts to full.
Double Heart

Picking up one of these refills two of Mike's hearts.
Lantern

Used to light up dark rooms deep within the caves.
Medicine

Bottles of medicine that can be collected and used any time during the dungeon. Each use restores five hearts.
Quadruple Heart

Picking up one of these refills four of Mike's hearts.
Rod of Sight

Mike ain't afraid of no ghosts as long as he has his rod of sight. Using it makes ghosts both visible and vulnerable.
Small Heart

A single heart that is dropped by enemies which refills one of Mike's health containers.
Star

The stars are sometimes dropped by enemies. Collecting five of these will refill one of Mike's health containers.
Try Your Luck Sign

Feelin' lucky? This sign can increase or decrease the number of Mike's lives by 0, 1, or 2.
Vitamin X

Fills all 22 of Mike's hearts. Any surplus of hearts over his total life level will degrade over time.