Ability over Appearance: During casting, they specifically looked for actors who could capture the spirit of their characters and waited until workshops to nail down the voices and costumes.
Awesome, Dear Boy: Tina Landau was unfamiliar with the franchise and rejected the initial offer to direct this show, thinking that it'd just be a cynical corporate cash grab. Then she saw some episodes of the series and found herself engaging with the characters and humor and changed her mind. In particular, she connected with Stephen Hillenburg's origins in experimental animation, and felt that they could capture the same grungy indie look in a theatrical setting.
Edited for Syndication: After the original airing of the televised version, an edited version began airing that removed "No Control", "Daddy Knows Best", "Poor Pirates", "Bikini Bottom Boogie", and "(I Guess) I Miss You".
Fake American: British Gavin Lee as American-accented Squidward.
Filmed Stage Production: A film of the show with most of the original cast aired on Nickelodeon during the time the production was touring, and was later made available on Amazon Prime. However, the staging was condensed and some moments from the original show were removed, such as Plankton and Karen's Big Damn Kiss.
Keep Circulating the Tapes: The official soundtrack recording is from the Chicago run, with the original cast and the original versions of the songs. The Broadway version of the soundtrack, the version used for the television live show, has not been given a professional recording.
The Original Darrin: The Chicago run featured Mark Ledbetter as the French Narrator; the Broadway run featured new lines recorded by Tom Kenny. The TV version, meanwhile, had him physically appear to reprise the role of Patchy the Pirate (a role played by Jason Michael Snow in the Chicago run and Jon Rua in the Broadway run).
The Other Darrin: In the televised version, there were a few notable cast changes:
Lilli Cooper, the original Sandy, was replaced by Christina Sajous, who replaced Cooper in the original run, since Cooper was appearing in Tootsie on Broadway.
Stephanie Hsu, the original Karen, was replaced by Katie Lee Hill, due to Hsu taping her recurring spot on The Marvelous Mrs. Maisel.
The Mayor is played by Bryonha Parham, instead of her original actress from the Broadway run, Gaelen Gilliland, who was traveling with the national tour of Mean Girls.
The Other Marty: Several actors changed from the Chicago pre-show to Broadway. In Chicago, Mr. Krabs, Pearl and Plankton were played by Carlos Lopez, Emmy Raver-Lampman, and Nick Blaemire respectively. On Broadway, they were replaced with Brian Ray Norris, Jai'len Josey, and Wesley Taylor. Same goes for Mark Ledbetter as the French Narrator and Old Man Jenkins (who are respectively replaced by Tom Kenny, reprising his role from the cartoon, and J.C. Schuster).
Promoted Fanboy: Ethan Slater is a huge SpongeBob fan, to the point that when he was handed the audition script he immediately recognized that it was from the animated series despite the character names being changed to maintain secrecy.
Repeating Ad: During the run up to and just after its official opening, ads for this musical were shown constantly during every bit of family-oriented programming in the NYC area. During the local broadcast of A Christmas Story Live, they appeared in every break during the second half of the event.
Role Reprise: Tom Kenny himself voices the French Narrator for the show's Broadway run. In the filmed version, he reprises the role of Patchy the Pirate.
Romance on the Set: Stephanie Hsu (Karen) and Allan K. Washington (Larry the Lobster) were married during the show's run (they tied the knot two months before the show debuted on Broadway). Funnily enough, Washington got the chance to play Plankton for a few performances, so you can bet that the romance between him and Karen was genuine.
When director Tina Landau was first approached to helm the musical, she originally declined, believing that she was being asked to direct a silly kids' show or theme park attraction. She eventually joined the project when she became fascinated with the cartoon's surreal "indie" humor; since she had a knack for experimental theater, Landau felt that the show's avant-garde nature had enormous potential for the stage.
Tina Landau: I thought what they were asking me to come in about was kind of a theme park show with big mascot costume heads, so I said no. And he said, "Wait a minute, [Stephen] Hillenburg, the creator of the show, comes from experimental animation and is a marine biologist, and he's really interested in some form that is indie".
The climactic scene where SpongeBob climbs to the mouth of Mt. Humongous was originally going to be done with a series of rolling ladders (much like the one the the Mayor uses in the show), but this was dropped in favor of the enormous ladder web that's used in the current show.
and actual giant bubbles