Jazz2K on 12 May 2011
Who says that Sony helped making the game and didn't just funded part of the development? Do we know what was the agreeing between From Software and Sony to say FS stole the engine and style to make a game on their own?
What I believe is that From Software wanted to make a sequel to Demon Soul but Sony decided not to publish the game (see what happened when they were supposed to publish it worldwide) so From Software went to another publisher which is Namco and they requested the game to be multiplatform.
