Nightmare Sphere (AKA: ナイトメアスフィア) is a free Castlevania-like and metroidvania-style doujin, indie game developed by 暁音♪ (AKA: n_sphere2, MickmanX, who used to be an art designer at Capcom) from Japan in 2009, using GameMaker Studio. It incorporates elements from classic 2D action video games like Metroid, Castlevania, Mega Man, and includes some degree of adult content.

Castlevania: Simon's Destiny is a free (non-profit), fan-made small game developed independently by Batandy with GZDoom engine, based on Konami's Castlevania franchise. This game was originally announced and released in 2017. It is completely standalone, not an MOD (so doesn't require DOOM2.wad), only GZDoom is required to play!

Castlevania, a horror action adventure game series created by the well-known game developer Koji Igarashi (いがらし こうじ, 五十嵐 孝司) from Japan, has been praised by numerous players around the world for its unique gameplay, diverse exploration and puzzle solving elements since it was first launched on the FC game console in 1986. So far, it already has a history of more than 30 years. In addition to games, it has also launched novels, comics, animations and other pan-entertainment multimedia. Therefore, its influence on future video games is self-evident.

Castlevania Double Pack has two previous great and complete Castlevania games on Game Boy Advance console in one game cartridge, they are: Castlevania: Harmony of Dissonance + Castlevania: Aria of Sorrow. It was licensed by Nintendo and released by KONAMI in 2006.

Akumajou Dracula X: Gekka no Yasoukyoku is the Japanese version (only sold in Japan) of the Castlevania: Symphony of the Night (悪魔城ドラキュラＸ ～月下の夜想曲～) originally released on PlayStation (PSone, PSX) console. It was published as the direct sequel of Akumajou Dracula X: Rondo of Blood, for Sega Saturn platform.