Metal Gear Solid creator Hideo Kojima has admitted to Famitsu magazine, via Siliconera, that it "would've been better" to release Phantom Pain and Ground Zeroes "all at once".
"It would've actually been better to release it all at once but by the way things are going, it appears likely that Phantom Pain will be coming out around the time the PlayStation 4 becomes more spread out. That means we would've had to make people wait a while longer."
Famitsu noted that creating such a vast open world game would surely take time and that players must be aware that there will be some wait before the game is released. Kojima replied saying:
"Prior to the announcement of Metal Gear Solid 5, last year, we showed a Fox Engine implementation vide. Then, we also showed the Fox Engine in a presentation video at GDC 2013. Since we revealed information on a regular basis, there were many who believed that Metal Gear Solid 5 was already complete, and there were many voices from fans saying 'we want to play it soon.'
"However, The Phantom Pain has enormous volume, so it will require much more time. So, together with the marketing staff, we consulted 'what ifs' and such, and came to the decision of allowing fans to at least play the prologue, ahead of time. We want to offer it for as cheap as possible, so at first we thought about making it as a download only; however, after thinking about people around the world, and how some places don't have the best connectivity, we're preparing a physical version."
Kojima also suggested that save files will carry over from Ground Zeroes to Phantom Pain suggesting gamers who play both will have access to additional content.
Both the PlayStation 4 and Xbox One versions of Ground Zeroes will have exclusive content when the game launches in early 2014.