Black Blood: The censored versions of the game replaced all of the blood with light blue water and recolored the reddish zombies to be bright green.
Blade on a Stick: Appropriately vague, since Lecarde's weapon could become a spear, an axe-head spear, or a trident.
Bloodier and Gorier: Out of all the Classicvanias, this one had the most blood in it by far. Though, coming from a Sega Genesis game, this is hardlysurprising. Yet somehow it got an "all audiences" rating.
Bowdlerize: In the European version, all the blood was removed.
Eric's death animation was also altered so that his spear didn't impale him.
Degraded Boss: Some of Stage 6's monsters were bosses in the earlier levels.
Denial of Diagonal Attack: Averted when playing as Eric, who can twirl his spear in all eight directions. Somewhat averted when playing as John, who can attack upper left, upper right, and downwards while jumping.
The Dragon: Drolta Tzuentes, who is actually the second-to-last boss after John/Eric defeated Dracula's first form, despite what the American manual says.
Dub Name Change: Johnny to John, though it's not too different compared to other examples.
Eric's spear became the Alucard Spear due to a mistranslation. You can imagine the Epileptic Trees this caused.
Easy-Mode Mockery: As per Konami game at the time, you have to beat the Expert mode to get the full ending.
Also, Drolta Tzuentes was based on on Bathory's real-life servant, Dorottya Szentes.
Incendiary Exponent: Upgrade your weapons enough times and they're on fire for maximum damage. Shame you lose it on getting hit once.
Interface Screw: The control-reversing pollen from the giant roses in Stage 5-1, as well as Stages 6-2 (where the screen splits into 3) and 6-3 (the inverted stage, and the vertical controls are reversed).
Nintendo Hard: It's bad enough that the game's difficulty gives Rondo of Blood a run for its money, but the limited continues are what really seal the deal. The Easy-Mode Mockery doesn't help either.
Official Fan-Submitted Content: Two enemies, a boss, and an obstacle were chosen from a contest for the Japanese exclusive MegaDriveFAN magazine. Those enemies were the green enemies in the gardens of Versailles, the beetles in the Munitions factory (which also housed the winning trap, the rollers), and the boss was the Silhouette Demon just before the Princess of Moss.
1-Up: These are often hidden in some rather hard-to-reach places.
Password Save: At the end of each stage, you get a password with number of lives and continues remaining.
Revenge: the main motive for Eric Lecarde to hunt down Elizabeth Bartley.
Rise to the Challenge: Stage 2-2 has water steadily climbing. As an Auto-Scrolling Level, you're free to climb up beyond the camera. In the next stage, you find the enemy that causes the water to rise, and need to kill it before you drown.
Super Drowning Skills: A little relaxed by this series' standards; falling into water doesn't kill you unless you fall off the screen; it simply causes you to take heavy damage. If you have low enough health however, it will kill you.
Timed Mission: Stage 2's Water Mage mid-boss, who floods the screen with water until he's dead. Take too long and you get to see Eric and John's Super Drowning Skills on display in the heat of battle.
Whip It Good: Morris steps in to keep this a Castlevania game.
World Tour: Unique among the series for its usage of this trope.
World War One: In the game's backstory, the Big Bad of the game, Elizabeth Bartley was the mastermind behind the Archduke of Austria's assassination, which started World War I.