Background
During the last seasons of Adventure Time, there was talk at Cartoon Network about concluding the series. Olivia Olson, who provided the voice of Marceline the Vampire Queen, said that since this discussion wore on for a while "the ending of the show was getting stretched and stretched and stretched". Chief content officer Rob Sorcher told the Los Angeles Times of the network's decision to end the series, saying:
"Adventure Time was playing less and less on Cartoon Network, yet we were moving towards a large volume of episodes. And I really began thinking '[The end] can't come quickly as a sudden company decision, it needs to be a conversation over a period of time.' And it did also strike me that if we don't wind this up soon, we're going to have a generation of fans graduate through the [television] demo[graphic that Cartoon Network targets] and we won't have completed a thought for them."
Consequently, on September 29, 2016, Cartoon Network confirmed that the series would conclude after its tenth season.
Development
The special was written and storyboarded by Tom Herpich, Steve Wolfhard, Seo Kim, Somvilay Xayaphone, Hanna K. Nyström, Aleks Sennwald, and Sam Alden, and Graham Falk. The story was developed by Herpich, Wolfhard, Ashly Burch, showrunner Adam Muto, head writer Kent Osborne, Jack Pendarvis, Julia Pott, and series creator Pendleton Ward. Former head background designer Ghostshrimp returned after having officially left the series during the fourth season.
According to Osborne, Cartoon Network provided the writers with "an opportunity to spend a lot of time thinking about the finale" before production ended. In an interview with TV Guide, Muto explained that the show's writers used many of the episodes preceding the finale to conclude minor character story arcs "so we wouldn't have to cram too much in at the very end here." This allowed the finale itself to be "less dense" by simply "hitting the big [beats] and then finding vignettes for all the characters ... so we could get snapshots of where they could end up."
Princess Bubblegum and Marceline kiss in one scene and are shown developing a romantic relationship in the special's epilogue. Muto said that the relationship was "an ongoing conversation... It certainly wasn't in the show's original pitch. It was a relationship that evolved over time." The outline of the episode merely called for the two characters to "have a moment"; Nyström, being responsible for the scene, was given creative control as to the nature of the "moment". Muto noted, "When Hanna boarded that, there was a little note in the margin that said 'Come on!' with a big exclamation point. That was the only note. I can't argue with that."
According to Pendarvis, storyline writing for the series ended in mid-November 2016, with the last storyline meeting being held on November 21. A tweet by Osborne revealed that the series' final script was pitched to storyboarders, with Alden and Nyström in attendance, on November 28. This episode was then pitched to the show's producers during the third week of December 2016. Voice recording for the episode ended on January 31, 2017, as confirmed by a number of cast members, including Maria Bamford and Andy Milonakis.
Like miniseries Stakes, Islands, and Elements, "Come Along with Me" features a unique title sequence. The sequence was animated specifically for the episode by Masaaki Yuasa's company Science Saru and storyboarded by Wolfhard.
Music
Former storyboard artist Rebecca Sugar returned to compose the song "Time Adventure", which BMO sings to Jake in order to calm him. Sugar said of the song:
"I wanted to write about how even if something ends, it continues to exist in the past, nothing ever really goes away, you only feel like it does because our mind has to process information one moment at a time in order for us to function as humans. I'm so nostalgic for the time that I spent working on Adventure Time and I find it comforting to think that I still exist in that office with Adam [Muto], working on those stories. I would be so happy to come to work and brainstorm with him and sit down and draw on paper and pitch these stories with Post-its tacked up to the wall, just like they did in the 1930s with the stick and the song and the dance, the most traditional way of doing cartoons."
When Sugar debuted the song at the 2018 San Diego Comic-Con, she joked that she wrote it "Because she can't stay away [from Adventure Time]." DiMaggio said that "The last day we recorded we had to do the final song that Rebecca Sugar wrote. I was a wreck when I first had to sing [... it was] like, 'Thank you, Rebecca Sugar, for your beautiful music.'"
Willow Smith guest stars in the special, providing the voice of Beth. She also recorded a cover version of the show's opening theme for the episode. Smith, a fan of the series, previously wrote the song "Marceline" based on the character for her 2015 debut album, Ardipithecus.
