Successfully complete Normal Boss Rush mode twice to obtain two Sound Discs. Play Normal Boss Rush mode again. Defeat Shaft, then get the hidden Key sub-weapon from the candles in the next pre-Boss room. Equip the Key, and defeat the next Boss to get the item to unlock Akoumajou Dracula Peke as a playable game at the main menu.
When the minotaur chases Richter in Stage 2, immediately fall into the first hole to enter the sewers. Complete the level as usual by defeating the Boss. You will then start Stage 3', the alternate version of Stage 3. Every time your path splits in Stage 3', always select the upper route. Use the Axe or Cross Boomerang sub-weapon to cut the vine-covered cage near the skeletal snake that is attached to a wall. Jump on the cage to allow Richter to jump to the upper ledges. Continue along the upper ledges until reach a breakable tombstone that contains the item that unlocks Castlevania: Symphony Of The Night as a playable game at the main menu.
In Stage 4, towards the end of the stage is an area where the lower section of a wall can be destroyed to reveal a bomb. Attack the bomb to destroy the rest of the wall. Enter the newly revealed area, go over the platforms, and kill the Axe Knights. At the end of this area is an item that unlocks the original Dracula X: Rondo Of Blood as a playable game at the main menu.
When the minotaur chases Richter in Stage 2, get the Key sub-weapon from the candlestick. Go down into the sewers after the minotaur gets blocked by the wall. Use the Key sub-weapon on the locked door at end of the sewer. This will trigger an intermission sequence showing Maria joining Richter. She can now be selected as a playable character at the main menu.
Defeat the first Boss on every level (Wyvern, Werewolf, Minotaur, Dullahan, Death, Shaft, and L. Vampire) to unlock Boss Rush Normal mode.
Defeat the second Boss on every level (Serpent, B. Golem, Dogether, Carmilla, Hydra, Shaft, and Shaft Ghost) to unlock Boss Rush Dash mode.
Defeat all Bosses, including Dracula, to unlock Full Boss Rush mode.
Save Maria in Stage 2, Terra in Stage 3', Iris in Stage 4', and Annette in Stage 7.
Attack with the whip, then tap Forward(2) immediately. Richter's whip will turn white and have a slightly longer reach. This can also be done while jumping or crouching if those buttons are also held during the Forward(2) sequence.
Successfully complete the game including the Inverted Castle with Alucard. Then, start a new game, and enter MARIA as a name to play as Maria Renard. Maria cannot level up or use any items.
Successfully complete the game including the Inverted Castle with Alucard. Then, start a new game, and enter RICHTER as a name to play as Richter Belmont. Richter cannot change forms, level up, or use armor, weapons, items, and magic. He can perform a super jump, a blade charging move, and use secondary weapons such as the throwing dagger, axe, and holy water.
Successfully complete the game with Alucard. Then, start a new game, and enter X-X!V''Q as a name to begin with 99 Luck. Note: There are two apostrophes in the name.
Successfully complete the game with Alucard. Then, start a new game, and enter AXEARMOR as a name to begin with the blue armor that transforms your character into the axe-wielding blue knight (Axe Lord).
Enter X-X!V''Q as a name. Note: There are two apostrophes in the name.