The Sega Saturn version of the game contains hidden files that can only be accessed when loading the game disc on a PC. 15 pieces of character artwork and a text document containing messages from 13 of the Saturn version's developers including graphic artists, members of the sound team, and programmers can be found. The messages contain insights about their duties, goals and struggles in porting the game from the PlayStation to the inferior Saturn, with several members of the staff having just entered the video game industry and joined Konami prior to work starting on the port. Collectively, they had mixed to positive feelings about the final result, with most being happy with their work, while others feeling they had failed to live up to the PlayStation version. Regardless, much of the staff thanked players for playing the game and encouraged them to mail feedback to them at Konami.

Two notable details from these messages include:

•A story/rant shared by programmer Hideto Imai in the last and longest message about his experience in violating Japan's Motor Vehicle Storage Act by parking his car curbside while staying at his in-laws during development.

•A scrapped character idea shared by graphic designer Yoshinori Suzuki:

Right before Richter fights Dracula at the start of the game, the two have a short conversation about his return and why humans summoned him back in the first place. In the original English localization of the game, Dracula says the line:


This line was not in the original Japanese script nor was it first written by translator Jeremy Blaustein for the game's English release. It originates from the 1967 essay "Antimémoires" by novelist André Malraux, who was France's Minister of Cultural Affairs at the time it was published.

In a 1997 interview with the game's director Koji Igarashi & designer Toshiharu Furukawa, they were asked how they came up with ideas for the game's huge assortment of weapons and items. Igarashi stated that they used a variety of different references, books and other materials, and tried to include things that had never been used in a Castlevania game before.

Furukawa added that each of the staff members had a special attachment to a different kind of blade, so they ended up using a good variety of blades in the final game. However, this bias did result in the developers' favorite weapons being overpowered, adding that "Not realizing that no one liked shields was a bit of a blind spot…"

In a 1997 interview with Koji Igarashi, found within the NTT-PUB official guidebook, he was asked how he came to hire Ayami Kojima as the game's illustrator? He responded:

"Wanting to do something different from previous Castlevanias, one of our first steps was to imagine an alluring new visual style for the characters. We decided then to search for an illustrator who hadn’t done much work with games, someone who was active in a whole different genre. As a team we went to bookstores and checked out book covers, buying the ones we liked and researching the artists. There were a number of candidates, but we felt that Ayami Kojima’s work had the rich, aesthetic direction we wanted for a new Castlevania."

In the NTT-PUB official guidebook, Koji Igarashi stated the team wanted to give players enough enjoyment with the game to match their money's worth by giving them more freedom to roam around to lengthen the playtime, unlike the previous Castlevania games which were shorter. To accomplish this, he inserted RPG elements like experience points and a level up system into the game so players would be more encouraged to challenge themselves against difficult enemies.

In the NTT-PUB official guidebook, Koji Igarashi & Toru Hagihara stated that in their early planning stages they came up with an alignment system. If the player used a lot of sub-weapons, they would gain a holy alignment; if they used a lot of magic, they would gain a dark alignment. There would be different endings based on the alignments with various subtitles, with Igarashi citing one as being named "聖魔のトリル" (seima no toriru), something like "The Trill of Light and Darkness." A trill is a musical ornament where two adjacent notes (i.e. 聖 "holy" and 魔 "evil") alternate rapidly. The reason for this feature's removal is unknown.

The development team's first idea for the game was to use the story and setting of Vampire Killer, and make the final Belmont vampire hunter the enemy. Another idea was to make Quincy Morris the person who defeated Dracula. They were also ordered by the "section chief" to make the “Ultimate Dracula” game. No one really knew what “ultimate” meant, but all the developers had talked it over, and the result was Symphony of the Night.

Orlox is based off of Count Orlok, from the classic 1922 vampire film Nosferatu.

The initial design for the Succubus boss featured her with her breasts fully exposed, as to be more in line with the lore of the character being a seductress. The team later decided to change this to cover her up.

The enemy who mourns the death of his pet owl after the player kills it was inspired by an enemy found in Super Castlevania IV, who mourns the death of his dog if it is killed before he is.

An early idea for the game was to feature skeletons that would replace candles that the player breaks. Considered more as a joke, the staff thought that if they included these skeletons, killing them before they had a chance to run away would result in the candles never reappearing after they were destroyed.

It was thought that, as the game takes place in Dracula's castle, Alucard should have his own room located at the top of the tall tower found to the right of the map. Within his bedroom would have been a character called the "Skeleton Carpenter", and as the game progressed the room would be built up with new furniture. There were thoughts of also including items and decorations throughout the game that the player could pick up and use to decorate the room. This feature was later cut from the game.

Plans for a special move to be used in tandem with the Sword Familiar called "Darkness Edge" were made, in which one would shout "Be sliced to pieces!" and the other would add "And die!" before both saying "Darkness Edge!" together. The move had dialogue recorded, but it was scrapped after the team couldn't come up with any idea on what the move would actually entail.

In the Japanese release, after Death takes Alucard's equipment away from him at the start of the game, Alucard makes an exclamation of dismay. This was removed from the English translation and changed into the exclamation of "What!?" that was used instead, as the team felt his dismay sounded "lame".

The scene was intended to make Alucard appear to have slipped up by becoming familiar with Death, and come across as his acknowledgement of his mistake, rather than appearing weak and whiny as it did during translation.

Koji Igarashi, the game's co-director, stated that the game's pause and inventory screen was originally supposed to feature more gothic framing, but due to time constraints, the development version of the frames (being simple white outlines) was left in instead. He claims that as a result of this, he learned to use slightly more finalized designs during development.

During the game's prologue, in which text scrolls up the screen explaining the story leading up to the events in Symphony of the Night, narration was recorded to be played over the top of the text in the English release just as there is in the Japanese release. This was removed prior to release, as Konami's PR team felt the recording was bad, and detracted from the scene.

The musical theme that plays during the game's title screen, "Prayer", features the phrase "Key Largo" repeated. This phrase is often used in Catholic Mass, and in Greek means "May your ascension into heaven be blissful." The track's vocals were performed by composer Michiru Yamane's younger sister, who does vocal work for a living.

After defeating the Hippogryph boss, Maria will ask Alucard if he knows Richter Belmont. When Alucard asks if he's from the Belmont clan, an 8-bit sprite will appear in a thought bubble. The sprite is of Trevor Belmont from Castlevania III: Dracula's Curse, which would be the Belmont he would most likely remember.

In the Japanese version of the game, dying as Alucard against certain bosses such as Succubus, Death or Richter triggers a special quote from said bosses instead of the usual Game Over music, with Richter notably having two. Another quote can be triggered if the player dies after meeting Maria in the Royal Chapel but before meeting Richter at the Colosseum

While the US and EU versions do not implement these, there are unused translated versions of Richter, Maria and the Succubus' lines, spoken by their English voice actors.

Maria: "I thought you might be the one. But, I was wrong."

Succubus: "Now, you'll be my own personal slave. Ahahahahahahaha!"

Richter: "Hah, I knew it! Only the Count is a true match for me!" / "More, fight more! My blood is not yet quenched!"

There is a confessional booth in the Royal Chapel area, complete with chairs that the player can sit on. If the player sits on the left hand side of the booth, Alucard sits and leans over to the counter, confessing sins. Sitting on the right will cause Alucard to sit normally as if to hear confessions while a female ghost appears, confessing her own sins or attacking Alucard depending on her color.

If a blue robed ghost priest appears, he sits on the right hand side and hears Alucard's confession, before crossing himself and sometimes leaving behind the Grape Juice item. In the Japanese version of the game (as well as all regional releases of the PSP port) the blue ghost speaks a line wherein he allows Alucard rest in said booth and offers a prayer to God.

While the blue ghost says nothing at all in the US and EU Playstation releases, an unused audio file can be found in the data of a perfect English translation of the blue ghost priest's line from the Japanese version.

"Come, son. Rest here. In the name of the Father, the Son, and the Holy Spirit. Amen."