Back in 1992, Game Freak – now most famous for developing the insanely popular Pokémon series of video games – produced an adaptation of Tatsuya Egawa's million-selling manga Magical Taruruto for the Sega Mega Drive in Japan.
Released exclusively in Japan in April of 1992, Magical Taruruto-kun was directed by Ken Sugimori, produced by Satoshi Tajiri and featured music by Junichi Masuda. All three have become a massive part of Pokémon's success on Nintendo platforms.
Magical Taruruto appeared in Weekly Shōnen Jump from November 1988 to September 1992, and would also spawn an 87-episode anime TV series by Toei Animation, as well as three feature films.
It's now possible to play the action platformer in English thanks to a translation patch by tryphon (thanks, @GaucheArtist).
It's listed as being in alpha, so expect some rough edges. You can download it here.
You can view the (untranslated) version of the game below.