In June 2023, a patch was released that altered and censored elements deemed insensitive and exploitative by Hidden Variable Studios, Future Club, and Autumn Games. This update was widely negatively received by fans and resulted in a review bomb on Steam lasting several days, gradually causing the Recent Reviews quality marker to dip into "Overwhelmingly Negative" until all reviews since the update's release were eventually frozen from the game's overall reception by Steam in response. Many of the fan reviews called the changes both a form of censorship and removal of paid content, and included, but are not limited to:

• The removal of in-universe allusions to real world hate groups and upskirt shots of teenage fighters.
• Toning down depictions of racial violence and other sexually suggestive content in the story.
• Deleting or altering several illustrations from the guest art gallery.
• The removal of several voice lines, most notably the Real Soviet Announcer voice pack due to previous allegations and ongoing lawsuits between Future Club and Mike Zaimont, the pack's voice actor and Skullgirls' former lead designer/programmer. This voice pack's removal especially drew criticism for previously being promoted as a $700,000 stretch goal during the 2013 "Keep Skullgirls Growing" Indiegogo campaign.

Current game director Charley Price stated that the updates were made in order to "reflect the values and broad vision for Skullgirls moving forward".

Finishing the match with any Blockbuster attack will cause the background to change and display a portrait of the defeated character with a pained expression on their face. This is a reference to the Capcom fighting game JoJo's Bizarre Adventure, which features similar portraits for when a match is finished with a Super. The shaders that Skullgirls uses for its portraits in-game are also internally labeled as "JojosDeathPortrait" in the game's files.

The cafe featured in Filia's story, MadMans Cafe, is a reference to the popular fighting game website of the same name. The artwork for the cafe is a parody of the Edward Hopper painting "Nighthawks".

One of Peacock's crouching attacks, "Curb Your Shoe", kicks the opponent with the Kuribo's Shoe from Super Mario Bros. 3

Filia's alternative color palettes reference several anime characters, such as Hatsune Miku from the VOCALOID series, Senjougahara Hitagi from animes "Bakemonogatari" and "Nisemonogatari", and Rei Miyamoto from Highschool of the Dead.

Ms. Fortune's winning quote, "Claws encounter of the furred kind!", is a reference to the 1993 video game Bubsy in Claws Encounter of the Furred Kind.

If Peacock uses the "Shadow of Impending Doom" special, there is a chance that she will drop a steamroller on the opponent, similar to what Dio does when using his stand, The World, in JoJo's Bizarre Adventure. Avery even makes a similar noise when attacking.

Fans of the Hasbro TV show "My Little Pony: Friendship is Magic" set out on making a fighting game called "My Little Pony: Fighting is Magic." Developed by a team of fans called "Mane6," the game would use locales and characters from the show. However, after receiving a cease and desist from Hasbro Corporation, Lab Zero Games added a stretch goal in their Skullgirls Indiegogo campaign to allow the Mane6 dev team to use the Skullgirls engine. The stretch goal was met, allowing Mane6 to continue their game with different assets.

According to Lab Zero Games, the total cost of adding a new character to the game's roster is more than $150,000:

Parasoul's level 3 blockbuster, Inferno Brigade, resembles one of BB Hood's supers from Marvel vs. Capcom 2 and Darkstalkers.

If Cerebella kills an opponent with her Battle Butt attack, "2000" will appear on screen in a similar fashion as when killing an enemy in Battletoads. This was an intentional reference placed into the game by Mike Z.

According to one of the artists behind Skullgirls, Umbrella's dialogue at the end of Parasoul's story mode is a reference to Terry Bogard's catchphrase "C'mon! Get serious!" in Garou: Mark of the Wolves.

Parasoul's kid sister, Umbrella, was originally going to be included in the initial release of the game, but was dropped early on in favor of Valentine and Double to increase the number of combat-capable villain characters. Unused graphics and voice clips for Umbrella can still be found within the game's files, although Umbrella would later become a DLC character in the game's first Season Pass in 2021.

Fukua was originally meant as an April Fools joke poking fun at Capcom's announcement of Decapre, a clone character for Cammy, being included in Ultra Street Fighter IV. However, due to fan feedback, she got to stay in the game.

The scene in Fukua's reveal trailer and story mode where Filia is asleep in bed is a reference to the ending of Super Mario Bros. 2.

Inside the game's files is an unused graphic with an alternate spelling of Squigly's name. It appears that it was meant to be used on the character select screen.

The Cathedral stage has pictures of Venus and Aeon seen in the stained glass windows. Both characters have only been seen in Double's ending, and had a chance of being downloadable characters during the game's Indiegogo campaign, but they were not chosen.

Umbrella's design seems to be inspired by the mascot of the salt-producing company Morton Salt.

When using Cerebella's Lock & Load move, there's a 0.2% chance that a crudely-drawn cat will randomly appear.

This was derived from one of the animators drawing a cat in one of the frames but forgetting to take it out. Mike Z insisted that the cat should remain as an Easter egg, with the staff agreeing on the condition that Mike Z would animate it himself.

The game was originally planned to have alternate endings for Story mode for most of the cast except Double. There is unused text of these alternate endings complete with dialogue for what appear to be choices the player would make.

Filia: Would wish for her memories back despite Samson's protests

Cerebella: Asks the Skull Heart to make Vitale Mecidi love her and only her. When she returns home, however, Vitale has gone mad and murdered everyone present except Feng just so he can have Cerebella all to himself. Feng kills Vitale only for him to get back up, turned into a monster. Cerebella and Feng flee to the country, hoping to start a new life.

Peacock: She wastes time making inane wishes that the Skull Heart could not possibly grant, much to the Heart's annoyance.

Parasoul: Seemingly kills Umbrella to prevent another Skullgirl from being made. Umbrella reassures her with her dying breath that she did the right thing.

Ms. Fortune: Goes ahead with her original plan to revive the Fishbone Gang. They are revived as mindless servants of the now Skullgirl Fortune.

Painwheel: Wishes for "Freedom". The Skull Heart frees her from human emotion and restraint, making her into an incredibly powerful Skullgirl.

Valentine: Seals the Skull Heart away to prevent it being used again knowing that it can't be destroyed so easily. However, when she faked a deception against Brain Drain, she killed a character named Christmas, who was close to Brain Drain. For the sake of revenge, Brain Drain forces a control mechanism on Valentine and turns her into the same abomination as Painwheel. As this happens, the Skull Heart mocks Valentine's efforts.