All of them where scrapped when Platinum Games took over
Yuji Korekado, a producer working on Metal Gear Rising: Revengeance, says that the game had a number of unique bosses early during the development cycle, some of them comparable to the best the series had to offer, before development duties were taken over by Platinum Games.The developer tells the Official PlayStation Magazine that, “The script was finished and the boss concepts were finished. The design was finished with those levels, and the levels were at the point where we could play it through in a white box – but we couldn’t come up with a core concept to tie it all together. In the end, we couldn’t finish the game.”
He adds, “We believe that the bosses we created for Metal Gear Solid: Rising were probably some of the best in the series, but Saito came in and said, ‘We’re not going to use these bosses.’ So you’ll not be seeing them this time around.”
The game started life as Metal Gear Solid: Rising and it was supposed to use the basic stealth template of the series, but the core mechanics were never satisfying and Kojima Productions decided to hand over development to Platinum Games.
The new studio chose to create a more action-focused experience and changed the name to Revengeance and the boss designs would just not fit in the current model.
It’s not clear whether Kojima plans to use the design in another Metal Gear title in the future.
Metal Gear Solid: Revengeance will be launched in early 2013 and will allow players to control Raiden, the cyborg ninja, as he battles a variety of new enemies and slices helicopters.
Hideo Kojima, the creator of the series, is working on Metal Gear Solid: Ground Zeroes, a game that will use the more familiar stealth elements of the franchise.