Two packages of Raiden IV are slated to come out in September, a limited edition and a Gamestop edition.
The limited edition, which is actually the standard retail version, comes with a soundtrack CD. The Gamestop Edition also comes with a secret file — a disc with concept art, enemy data, and game strategies.
While hard to get, the secret file was released in Japan. It came with the Raiden IV: Ultimate of Raiden bundle released by INH Group.
Update: UFO Interactive sent us a note that the secret file is actually a computer file in North America. Users will be able to download the data to a computer. The disc is just for Japan.
Here’s a look at what’s inside the secret file.