Code, graphical assets, and strings can be found in the game's files for the character Matt the Radar Technician, Kylo Ren's alter ego from the Saturday Night Live sketch. The character was removed from the game late in its development due to legal reasons.

During the 2013 Skullgirls Evo Breast Cancer Donation Drive, anybody who donated $50 USD could request a personal voice message from the voice actors of the game. One of the requests was for Peacock's voice actress, Sarah Anne Williams, to sing the song "Yakko's World" from the popular 90's cartoon Animaniacs.

In the Japanese version, there is an optional sidequest accessible by linking Lunar Knights with Mega Man Star Force through WiFi and entering a modified version of the Konami Code. This side quest is unavailable in all international versions.

The team originally wanted to give the AI the ability to change it's tactis depending on who it was fighting against, such as the computer knowing how close to stand to each individual opponent, etc. This feature was removed due to time contraits.

The characters were originally going to recieve more damage when dizzied. This feature was removed due to time contraits.

The team originally wanted to give "weak points" to the characters. When the characters where hit in said weak points, they recieved more damage. This feature was removed due to time contrainsts.

The team originally wanted to introduce character intro animations, but they were scrapped because of lack of memory. The only renmant of this idea is the sequence of M.Bison (Dictador) removing his cape before starting the match.

The team originally wanted to include stage hazards into the game such as projecticles blown by the wind that the player had to dodge, but the idea was scrapped early on.

During early development the team had the idea of the game's story being centered around an abandoned island that had been purchased to host a tournament featuring fighters of all different styles. This early draft of the story is reminescent of the 1973 film Enter the Dragon.

Early sketches suggest that Vega was going to resemble a medieval knight wearing a full suit of armor. He was also simply named "Spanish Ninja" by the developers until he was finally given a name.

During the early development of Street Fighter II, many characters had placeholder names until they were given proper ones:
•Zangief was referred to as “Vodka Gorbavsky".
•Chun-Li was named "Chinese Girl"
•Blanka was called "beast"
•M.Bison (Dictador) was named Washizaki (鷲崎 "Eagle Cape"), likely a reference to the villian of the same name from the manga series Riki-Oh.

During the development of Street Fighter II, an early design for Dhalsim bore a striking resemblance to Ganesha, a Hindu god with four arms and the head of an elephant. His name around that time was Naradatta’, which may refer to a character in Osamu Tezuka’s manga Buddha.

Ace was originally going to be featured in his own side-scrolling mode. However the team faced problems during development, including certain moves that the player could "slip through" with good timing, such as Darun’s Indra Bahsi and Doctrine’s wire.

The cycloid were created with the intention to give a "strange vibe" to the players. Cycloid – β, in particular, was designed in order to see if the development team could introduce elements such as mirror surface processing, refraction of light through transparent objects, and representation of flames, all of which were very popular elements in programming around the time of the game's release.

During development Hayate's "Heat Haze Vortex Climax" was simply called 'UFO', before it was finally given a proper name.

The reason all 3 phases of the final battle with Brevon were given health bars (the first two subtly indicated by the two pillars in the background) was due to it being hard to gauge how close it was to defeating them, as well as their difficulty.

Both Superman and Batman's "Super Moves" are a reference to their own Hollywood films.
When Superman performs his "Super Move" he'll beat his opponent in the sky, the same way he did with General Zod in their final battle from "The Man of Steel". And when Batman performs his "Super Move", he'll summon the Batwing to drag his opponent up to the sky, pausing in front of the moon to make the Batman symbol, the same way it did in Tim Burton's 1989 Batman movie, when Batman fought against the Joker.

Demitri's Midnight Bliss attack turns Ryu into a young girl with a siver jar. This girl is the same one that appeared in Street Fighter II: The Animated Movie.

The first level in Doom was actually created last. This is because John Romero wanted experience in level designing so he could make the first level his best.

In the US release of the Game Boy Advance port, a hidden developer message can be found in the game's files. The message is of a copypasta that circulated via emails and groups during the mid-90s. The message reads:

I LIKE MONKEYS. I like monkeys. The pet store was selling them for five cents a piece. I thought that odd since they were normally a couple thousand each. I decided not to look a gift horse in the mouth. I bought 200. I like monkeys. I took my 200 monkeys home. I have a big car. I let one drive. His name was Sigmund. He was retarded. In fact, none of them were really bright. They kept punching themselves in their genitals. I laughed. Then they punched my genitals. I stopped laughing. I herded them into my room. They didn't adapt very well to their new environment. They would screech, hurl themselves off of the couch at high speeds and slam into the wall. Although humorous at first, the spectacle lost its novelty halfway into its third hour. Two hours later I found out why all the monkeys were so inexpensive: they all died. No apparent reason. They all just sorta' dropped dead. Kinda' like when you buy a goldfish and it dies five hours later. Damn cheap monkeys...I didn't know what to do. There were 200 dead monkeys lying all over my room, on the bed, in the dresser, hanging from my bookcase. It looked like I had 200 throw rugs. I tried to flush one down the toilet. It didn't work. It got stuck. Then I had one dead, wet monkey and 199 dead, dry monkeys. I tried pretending that they were just stuffed animals. That worked for a while, that is until they began to decompose. It started to smell real bad...I had to pee but there was a dead monkey in the toilet and I didn't want to call the plumber. I was embarrassed...I tried to slow down the decomposition by freezing them. Unfortunately there was only enough room for two monkeys at a time so I had to change them every 30 seconds. I also had to eat all the food in the freezer so it didn't all go bad...I tried burning them. Little did I know my bed was flammable. I had to extinguish the fire. Then I had one dead, wet monkey in my toilet, two dead, frozen monkeys in my freezer, and 197 dead, charred monkeys in a pile on my bed. The odor wasn't improving. I became agitated at my inability to dispose of my monkeys and to use the bathroom. I severely beat one of my monkeys. I felt better. I tried throwing them way but the garbage man said that the city wasn't allowed to dispose of charred primates. I told him that I had a wet one. He couldn't take that one either. I didn't bother asking about the frozen ones. I finally arrived at a solution. I gave them out as Christmas gifts. My friends didn't know quite what to say. They pretended that they like them but I could tell they were lying. Ingrates. So I punched them in the genitals. I like monkeys.

This same message can also be found in the Game Boy Advance release of Hot Wheels: Velocity X which was also developed by Saffire Corporation.