Memory Orbs are gameplay items found inside memories in To the Moon, Finding Paradise and Impostor Factory. In the first two games, they are used to break the barriers of mementos, and in some memories, they are also needed unlock more areas; while in the latter, there are no memento objects, and instead the orbs are used to break the barrier of "gates" connecting two memories together. Therefore, obtaining them is essential to proceed through the games.
Description[]
Memory orbs are a construct of the Memory Editor, and therefore aren't actual, physical objects existing in a patient's memory. There are up to 5 orbs in a single memory, which are depicted as shiny balls with the colors 
red, 
green, 
blue, 
yellow and 
purple.
Obtaining[]
They can be obtained by interacting with certain objects, watching events unfold and exploring certain areas.
Mementos never give memory orbs.
Usage[]
Breaking memento barriers[]
The amount of orbs that can be found in a single memory is the same amount needed to break the memento's barrier. Thus, the player must find all the memory orbs before they can proceed to the next memory.
The orbs are used by interacting with the memento (or memory gate in Impostor Factory). The controlled character will fire the orbs towards the memento (or gate), cracking the barrier and breaking it when the last orb is used. The player does not have to have all the orbs to start using it on the memento.
Since memory orbs are introduced in the second memory, the first memento needs no orbs to access.
Unlocking areas[]
In some memories, some areas are locked and require memory orbs to enter. In other words, those areas cannot be accessed before exploring other areas first. Attempting to enter a locked area will give the prompt: "Requires X 
to proceed." with X being the number of orbs. A locked area may also require an orb of a certain color.