According to the game's producer, Motohiro Okubo, the title's code name was "Luxor" due to the team's intentions on making the game feel brighter like it was in the first Soulcalibur.

Winning in-game the Happy Lucky Lottery isn't actually based on luck at all but on the date from when you bought the ticket based off of the GameCube's internal clock. The prizes are as follow: 4th prize is anywhere between 4 to 10 days, 3rd prize is 25 to 35 days, 2nd prize is 85 to 115 days, and 1st prize is 335 to 395 days. If you change the system's clock to a day prior and went back to talk to Lucky who runs the lottery, he'll know that the internal clock has been messed with. You can either admit to it or lie to not having tampered with it, however you'll need to pay 500 coins in order to reset the lottery, regardless. Daylight savings is not put into account. Buying a new ticket won't actually increase your chances of winning either but will instead reset the days back to 0 from when you bought it.

Daisy and Waluigi were intended to be unlockable characters at one point. They are made available from the beginning in the final release.

According to programmer Jon Burton, Knuckles' bonus stages were planned to have their own music. However, due to memory constraints, the song couldn't fit onto the cartridge, and Knuckles' bonus stage simply use Tails' bonus stage music in the final game. The song was eventually repurposed in Sonic Adventure as "Pleasure Castle" (Twinkle Park 2).

Originally, Ken was going to have more moves, but that idea was scrapped, due to his "Shoryuken" move being too strong.

One of Captain Cold’s Combos is called “Prison Break”, a reference to the TV show of the same name.

In an interview, Noboru Sugimura stated that Leon was originally supposed to start out in civilian attire. There would've been a scene between him and Marvin at the police station where he'd change into his police uniform.

"It’s true that with Racoon City destroyed, the police wouldn’t be actively on duty, so there’d be no real need for Leon to change into his uniform… but we wanted to show his determination to protect both the city and his principles by having him change into his uniform regardless. It was a scene with a lot of meaning. Unfortunately, due to a problem with the CG it got cut."

According to an interview with Neil Druckmann, Cassie Drake was originally going to be a male character, but this was change their female lead character concept artist. The artist wanted Nate & Elena's child to be a girl, and Neil was convinced by her decision.

The game's director, Tokuro Fujiwara, decided to make Tomba! a 2D side-scrolling game because because of how many 3D games that let you move anywhere were on the market. He felt that 2D allows players to feel the fun and excitement in a straightforward way.

In an interview, Naoto Oshima was asked if the blue birds were a direct reference to the game Flicky. Oshima said yes, and also mentioned that he asked game's designer Yoji Ishii's permission to use Flickies in his work.

Sefton Hill stated on reddit that they were originally going to include an interactive combat battle against Rocksteady employees, in the game's credit. And each time the player got a knockdown, the developer's names and roles in development to appear during the slow-motion. It would've been used for the new game plus, but due to time constraints, they have to remove this feature.

The game has an unused background that uses graphics from Wrecking Crew.

The sound effects Yoshi makes are noises made by Kasumi Totaka sped up.

According to Ken Sugimori, the Pokémon that appeared in the front page of the 1997 edition of MicroGroup Game Review showcasing Pokect Monsters 2 were not supposed to appear in the game at all. While some were never to be seen, Tyranitar ended up being used. This explains why Tyranitar wasn't in the leaked 1997 prototype ROM.

When Pit gets Star KO'd, he'll shout out that he never learned how to read. This is likely a reference to a scene from Kid Icarus: Uprising Spoiler:when Palutena cuts off his power of flight upon defeating Pyrrhon.

Despite appearing in the box art, the Triceratons do not appear in the game itself.

While in an interview with Valve News Network in February of 2018, Gray Newell (Son of Gabe Newell) revealed that the final boss of Half-Life, the Nihilanth, represented him as a baby, stating "The Final Boss of Half-Life 1 actually the 'giant evil baby monster' is supposed to be me. When my mother was in childbirth they were thinking 'what's something really scary,' and at the time, having a child seemed to be the most scary thing to everyone."

In an Dengeki and Marukatsu Megadrive magazines interview, game's graphic designer Toshio Yamamoto stated that his team didn't use a planning document for the game.

Makoto was originally planned to be introduced in "Street Fighter III 2nd Impact: Giant Attack", but time restrictions led to her not being included.

During development, Ayla's animations sported bouncier breasts, but this facet of her animations was toned down before release.