999 is the first game in the Zero Escape series. Zero Time Dilemma is the third entry in this popular cult classic series that is raved by fans and critics alike. Since this third game is being released on Steam as well on Vita and Nintendo 3DS, there is a possibility of the earlier games making their way to these platforms as well.
999: 9 Hours 9 Persons 9 Doors was the first entry in the Zero Escape series that was originally released on the Nintendo DS and then later ported to iOS. Since the game is backwards compatible for the Nintendo 3DS, there was no need to port it to the platform but it looks like the Vita and Steam port is being teased by the creator of the series, Kotaro Uchikoshi.
He made a set of tweets first hinting at a Steam release with the comment “STEAMship” and then later clarified that the tweet was meant to read as “vital steamship.”
Sorry. Maybe my previous tweet should have been written as follows. "It looks like a vital steamship." Thank you!
— Kotaro Uchikoshi Eng (@Uchikoshi_Eng) June 10, 2016
While this looks like far fetched for a Vita release aside from the Steam version, which has been hinted earlier by the developers, it won’t be unusual to see because Vita already has the second entry in the series: Zero Escape: Virtue’s Last Reward, and can benefit with getting the original entry along with the sequel to Zero Escape 2.
In any case, we might get an official confirmation at the upcoming E3, set to start on June 13th in Los Angeles.