you are right @buzz
Another World:
Sequels
Eric Chahi has stated that he wishes the game to have no sequels as he wants the ending to the original to remain ambiguous so that fans could make their own conclusion to the franchise. Despite this, games have commonly been assumed to be sequels to Another World.
Spoiler warning: Plot and/or ending details about Heart of the Alien follow.
A non-canon sequel entitled Heart of the Alien was released for the Sega Mega-CD in 1994. The game was similar in visual style to Another World, although Heart of the Alien's programmers opted instead to use standard sprites instead of Chahi's 2D polygonal style, as they were quicker and easier to implement. The player takes control of the alien who befriends the protagonist in the original game and the backstory to the game is elaborated on. It is commonly mistaken for a midquel, probably due to the presence of (monochromatic) flashbacks in the game's introduction, which show the events of the first game from the alien's point of view.
Chahi had nothing to do with the development of the game, beyond suggesting Lester's death, and he has since regretted that decision stating that he did not like it because it made a definite conclusion to the story, which Chahi had deliberately left open-ended.
Flashback:
The 1992 game Flashback and its 1995 sequel Fade to Black (both also from Delphine), were often mistaken for sequels to Another World because of similar gameplay and graphics. However these games have nothing to do with Another World, except said similarity in graphics or gameplay and had completely different stories. Both games were also made without the involvement of Chahi.
for the record, Eric Chahi, its the creator, of the both games.