The game is only officially available for PlayStation 3 and Xbox 360.
It is important to clarify that an official PC version of was never released. While most titles in the Ultimate Ninja Storm series, including the original Storm 1 , 2 , 3 Full Burst , and 4 , were eventually ported to PC via Steam, Generations remains a console exclusive for the PlayStation 3 and Xbox 360. The game is only officially available for PlayStation
You must own the original disc or game files to legally use an emulator. What Makes "Generations" Unique? including the original Storm 1