Sony is asking PSP developers to release downloadable versions of their games so they can played on its new NGP handheld.
Speaking in an interview with Japanese site Impress Watch, as translated by Andriasang, Sony boss Kaz Hirai explained that Sony's new handheld device will be backwards compatible with PSP titles but only those that have been made available as downloads.
As a result, Hirai added, Sony has asked developers to release digital versions of their games.
Hirai also explained that PSP games will run completely through emulation on its new portable system, which was unveiled in Tokyo earlier this week. Users will be able to transfer over any games already downloaded on their PSP as long as they are still within the download limits set by PlayStation Network.
The majority of PSP games are currently available as downloads through PlayStation Store. However, there are a few notable exceptions, including most recently Square Enix's Kingdom Hearts: Birth By Sleep.