The secret bonus Julius mode pays homage to Castlevania III: Dracula's Curse. The party members are Julius Belmont (descendant of Trevor Belmont), Yoko Belnades (descendant of Sypha Belnades), and Genya Arikado in his Alucard form. While there is no one that plays like Grant D'nasty in this mode, looking through the game's ROM reveals dialog that suggest Hammer was going take his role.

In the Subterranean Hell you can play a version of the old carnival game "Test Your Might".

The enemy "Chronomage" was inspired by the White Rabbit from "Alice in Wonderland". His description reads "Rabbit that uses a clock to stop time. Strict in regards to tardiness."

There are three items hidden in the castle that serve no purpose except as inside-jokes and trophies.

The Hidden Bell - Located in the Dark Chapel in the bell room. Using the Hippogriff soul super jump into the first bell, doing so a special bell will fall out.

The Hidden Crown - Located in the huge vertical portion of the Demon Guest House the part with the chandeliers. Head up to the room in the southeast corner that contains a single Waiter Skeleton and a chair. Sitting in the chair for a few seconds and a crown will emerge from the ground, just like the original Castlevania.

The Hidden Konami Man - The old school mascot for Konami is located in the Cursed Clock Tower. Visit the room with a single Slime and Tanjelly and then crouch in the spike-free area for one second. Konami Man will fly across the screen in all his 8-bit pixelated glory.

When using the Killer Clown bullet soul, the portraits on the cards are:
• Jacks - Yoko
• Queens - Mina
• Kings - Hammer
• Aces - Celia
• Jokers - Alucard

One of the boss characters, Zephyr, utilizes time stopping abilities in conjunction with knives, much like Dio Brando from the manga series JoJo's Bizarre Adventure. In the Japanese version of the game he shouts "Time has stopped"(時よ止まれ,Toki yo Tomare) which is one of Dio's catchphrases.

During the player's initial run of the game, the Japanese version disallows you the ability to skip cut-scenes, but you can skip cut-scenes in the international versions by pressing "Start."

In a Reddit AMA with Shutaro Iida, he revealed that, for him and his team, the most insufferable thing about developing this game and for the Nintendo DS was strict demand from higher ups "to use the touch [screen technology] as much as possible" during their development.