A few interviews with several of the cast members of the Harry Potter and the Order of the Phoenix video game have surfaced online. They talk about the different aspects of the video game.

These videos can be seen on YouTube:
Tom Felton
Rupert, Bonnie and Emma
On creating the characters
On creating the music
Matthew Lewis & Katie Leung

Source: HPANA & Veritaserum

UPDATE: Two futher videos, featuring Rupert, can be seen here and here thanks to RG.net! Another featuring Emma can be seen here thanks to EW.net!