One Week at Flumpty's was the original third and final installment of the ONaF series, but it was later cancelled. The Flumpty series was thought to be dead until the announcement of One Night at Flumpty's 3 in August 2020 as part of The Fazbear Fanverse Initiative.
- May 1st 2015: At Jonochrome's twitter account and the Game Jolt of ONaF 2 (though the Game Jolt picture has been taken down), he posted a teaser that is a parody of the 1st FNaF4 teaser, Nightmare Freddy, and that the text said that ONaF 2 used to be the final chapter. It also has Flumpty in it, but he has 6 arms on both of his sides, but it only shows the left side of Flumpty's new design. When brightened you can see the words, "I want to make other stuff please forgive me."
- The second teaser has nothing in it instead of the text : "This time, it is no yolk." and a small text saying "One Week at Flumpty's" under it. When brightened you can see a line of even smaller text stating, "Bear with me though, I've still only barely started making it. It's going to be awhile!"
- May 19th: A video teaser was released, and was titled "A Brief Teaser". This video was 15 seconds in length, and gave very little new information.
- May 20th: A video was released, entitled: "Vlog|Why a Third ONaF Game?". The video is 8:38 in length, and is a developer commentary where Jonochrome explains why he said he was not going to make a third game, and then did. During the video, he talks about how his Riddle series continued on for many separate games, because many people wanted more. This can mean that the ONaF series will continue even though he does not want it too.
- In a twitter post Jonochrome stated, "Since I've been negative lately, it's time for a positive One Week at Flumpty's tweet. There's slated to be 15 cameras."
- May 24th: Jonochrome tweeted, "Alright, massive spoiler time. The reason there can't be a custom night is because each night is planned to focus on different characters."
- May 30th: Jonochrome tweeted a picture with a caption. The caption read, "If it makes anyone feel better, here's a tease." The picture is a toilet paper roll next to a toilet. The toilet is casting a shadow to the right. This lead the fan base to believe that The Beaver would make an appearance in One Week at Flumpty's.
- May 31st: Jonochrome released a picture of the office for One Week at Flumpty's. The caption read, "This is a question more than a teaser. undecorated office looks like this right now; not set in stone. Any thoughts? ". The Picture can be found below in the gallery.
- June 13th: Jonochrome released a video explaining why he cancelled the game. Also giving a downloadable file in the description, of what he had completed. On this same day, the One Week at Flumpty's subreddit was created where in a small Reddit Dev team started progress on attempting to finish One Week at Flumpty's, with Jonochrome's permission, gratitude and encouragement.
- August 31st: Jonochrome released a canonical image to Twitter to follow up the cancellation of One Week at Flumpty's, confirming that Flumpty is no more and he will not be making any further Flumpty creations.
- April 1st 2018:Jonochrome made a fake trailer of One Week At Flumpty's intended as an April Fools joke and published it on his YouTube channel. His comment on the video reveals that this video is the canon One Week at Flumpty's, despite it being a joke.
Jonchrome decided to cancel OWaF. He had finished most graphics, and had completed Birthday Boy Blam in Night One. In the description on his YouTube video he gave a downloadable link to the graphics, code of the game, and the unfinished Night One. He also mentioned that there was something he left of the game in secret, as he thought the idea was great so he kept it for another game and not One Week at Flumpty's.