Exp Orb

Exp Orbs are floating diamond things given off by defeated Demons. Generally, demons will release some exp orbs whenever they are reduced to a Core, or when one phase of the demon is defeated, and then some more when they are fully destroyed. However, if they recover from a core back to a full form, they will not release any when reduced to a core on any further occasions. Exp orbs float towards the player character at all times.

Colours of Exp Orb
There are three colours of exp orbs. All of them contribute to level, while the latter two colours have other properties.

Yellow
Yellow exp orbs form 68.75% of all exp orbs. They only contribute to gaining Levels.

Cyan
25% of all exp orbs are cyan, and contribute to gaining Tiers as well as levels.

Blue
The remaining 6.25% of exp orbs are blue. These heal the character who collects them by a small amount. They also contribute to gaining levels, but not tiers. The amount of healing is determined by maximum HP, and is equal to maxhp/40 + sqrt(maxhp), rounded down.

Trivia

 * If any exp orbs are onscreen when leaving the current room, they will be automatically collected. However, due to an oversight, blue exp orbs only recover 1 HP when collected in this way. Aurora decided to keep this in because he thought it was amusing.