To access the Halloween Update Backstage to experience new features, either the player must first talk to the Desk Man, who also has some new dialogue, after beating Hard Mode or find the secret path that has been added to Fazbear Hills.
- 8 new characters were added:
- Jack-O-Bonnie - The animatronic from the fourth game's Halloween update patch. He is unlocked when beating the FNaF 57: Freddy in Space minigame.
- Jack-O-Chica - The animatronic from the fourth game's Halloween update patch. She is unlocked when beating Foxy Fighters.
- Nightmarionne - The animatronic from the fourth game's Halloween update patch. It is unlocked when beating Foxy.EXE.
- Nightmare Balloon Boy - The animatronic from the fourth game's Halloween update patch. He is unlocked when beating Foxy Fighters with an A rank.
- Purpleguy - William Afton in 8-bit styled appearance. He is unlocked after collecting all cupcakes in the FNaF 57: Freddy in Space minigame.
- Animdude - A smaller version of Scott's boss form. He is unlocked after beating the Chica's Magic Rainbow minigame after 3 minutes.
- Mr. Chipper - A character from Chipper and Sons Lumber Co. He is unlocked after beating the Chica's Magic Rainbow minigame.
- Coffee - A character from The Desolate Hope. He is unlocked after beating the FNaF 57: Freddy in Space minigame without collecting upgrades.
- 2 new areas, Halloween Update Backstage and Geist Lair, are added.
- 4 minigames are featured:
- 6 new enemies are added:
- Jangle - An enemy fought in Geist Lair.
- P. Goon - An enemy fought in Geist Lair.
- Neon - An enemy fought in Geist Lair.
- Souldozer - The antagonist in The Pilgrim's Progress game and a boss in Foxy Fighters minigame.
- Scott's Head - A boss from the FNaF 57: Freddy in Space minigame.
- Chica's Magic Rainbow - Final boss.
- 9 new attacks are added:
- Mega Virus
- 4th Wall
- Hocus Pocus
- Bubble Breath
- Balloons 2
- Neon Wall 2
- There are also few miscellaneous changes and add-ons:
- A brand new attack type was added, used exclusively for some of the new Update 2 characters, the color for those moves is a Blazing Orange.
- Nightmare Fredbear's Bad Pizza attack is replaced by the Freddles attack.
- 8-directional movement was added in.
- DeeDee now takes much longer to reappear.
The update's development has begun around February 2016. On February 18, 2016, fnafworld.com was updated, featuring the Halloween animatronics (excluding Nightmare Mangle), Chipper from Chipper and Sons Lumber Co., William Afton (using his Five Nights at Freddy's 3 8-bit sprite), and Coffee from The Desolate Hope. An update to the IndieDB page also featured Scott himself (as his avatar) as a playable character.
On March 30, 2016, fnafworld.com was updated again, having an easter egg at the top-right corner of the screen, showing Foxy, JJ, and Toy Chica riding planes, which debuted the "Foxy Fighters" minigame.
On April 1, 2016, a kitten from one of Scott's older games, Kitten In The Crowd, appeared as an April Fool's joke. It was removed the next day. The kitten can be found in the minigames Foxy.EXE, and FNaF 57 Freddy in Space.
On May 1, 2016, a rainbow with buckteeth, later known as Chica's Magic Rainbow, appeared.
Two days later, Update 2 was set to be released on May 13, 2016.
- Scott Cawthon has confirmed that there will be no Update 3.
- When Update 2 first launched, a bug caused the fan trophy to be removed, even if the player has all 48 characters. This was later fixed in v1.24.
- This is the first game in the Franchise to have credits at the end of the game.