Monster World IV (モンスターワールドIV, Monsutā Wārudo Fō?) is an adventure platform game, developed by Westone and released exclusively in Japan by Sega for the Mega Drive in April 1994. It is the sixth and final game in the Wonder Boy/Monster World series. It was later released for the PlayStation 2 as part of the Sega Ages 2500 series under the name Sega Ages 2500 Series Vol. 29: Monster World Complete Collection (セガエイジス2500シリーズ Vol.29 モンスターワールド コンプリートコレクション, Sega Eijisu Nisengohyaku Shirīzu Boryūmu Nijūkyū: Monsutā Wārudo Konpurīto Korekushon?). It was released on the Wii's Virtual Console service in Japan on January 15, 2008. An English-language version was released in North America and Europe for Virtual Console on May 10, 2012, with a release on Xbox Live Arcade and PlayStation Network to follow on May 22, 2012.

Motobug the Badnik in Sonic the Hedgehog (aka Motobug in Sonic 1) is a hack of Sonic the Hedgehog for the Sega Mega Drive, by Polygon Jim. As its title suggests, in this hack the main character Sonic the Hedgehog is replaced by Motobug, one of Dr. Robotnik's badniks.So far, some of Sonic's main sprites and animations have been replaced by those of Motobug, Motobug's speed has been decreased (except when powered-up by aSpeed Shoes monitor, which are more numerous), and the sprites of Roller badniks in Spring Yard Zone have been replaced by those of Sonic (referencing a common interpretation by fans that Roller is a robotic impersonation of Sonic, something that officially appeared in later games in the form of Metal Sonic and various others).Of the first release, Polygon Jim stated that he had only tested and confirmed Green Hill Zone (Acts 1-3) for completability. However, upon testing, Katelynn andRGamer2009 reported that other Acts are completable, including:Marble Zone Act 1Spring Yard Zone Acts 1 and 2Labyrinth Zone Acts 1 and 2Star Light Zone Acts 2 and 3Final Zone

Mystic Defender is a two-dimensional action video game released for the Sega Genesis system. Originally titled Kujakuō 2: Geneijō (孔雀王2?) in Japan and based on the anime/manga Kujaku Ou, it is the sequel to SpellCaster for the Sega Master System.