As an Easter egg in Nuketown Zombies, being activated by finding three teddy bears scattered around the map by holding the "use" button in front of them (on Original difficulty only). One is found on a seat in the bus, one is found on top of the bunk-bed on the top floor of the yellow house, and one is found outside the fence of the garden in the backyard of the green house.
As an Easter egg in Mob of the Dead, if the player does not move at all in the spawn room while in Afterlife and completely bleeds out. This version is shorter and grants a unique ending screen.
As an Easter egg in Der Eisendrache: when the player goes to the bedroom, a small music box can be found with a small Samantha Maxis from Moon in it. It's activated by holding the use button while aiming at it.
As an Easter Egg in Zetsubou No Shima, by filling up the bulbs near the purple 115 water with certain amounts of water.
At the end of the composition, Samantha Maxis will say "Shh, Do you hear the voices?".
In the Der Eisendrache music box, most of the song was altered to be in major, giving it a more upbeat tone than the original gloomy one.
The Zetsubou No Shima version is different as well.
Gorod Krovi features a similar song known as Samantha's Sorrow. It was mistaken as a rendition of Samantha's Lullaby due to no official name being attributed to the song before it was added to the Music Tracks in the 1.15 patch for Call of Duty: Black Ops III on August 16, 2016, along with the other songs from Gorod Krovi.