In Stage 5 of Castlevania: Rondo of Blood, there is a secret passageway that can only be accessed by Maria. It leads to a white object resembling a mirror or doorway that cannot be interacted with. In the PSP remake, a Soundtrack item can be found here.

There are a large number of unused dialogue pieces in the Symphony of the Night's data, including what may be an unused ending. Many of these sound files are alternate versions of voices that are already used in the game, but extended or slightly different.

A series of clips can be found in the game's sound files, which seem to be an unfinished ending. It seems to suggest that Maria intervenes in the fight between Alucard and Richter, where she becomes possessed or transformed by Shaft. It includes both winning and losing quotes, and ends with Alucard reflecting on the apparent death of both Richter and Maria. While the PlayStation Portable and Saturn versions allows a fight with Maria, it is not under these circumstances. There are no other suggestions towards this ending, but it is assumed to be an alternate ending during the fight with Richter when not using the glasses.