akira kurosawa build engine cd-rom central processing unit charlie wiederhold dos dean wesley smith digital media duke nukem forever e-mail entertainment software rating board expansion pack first-person shooter gnu general public license gt interactive game engine george broussard japan joystick kagemusha katana ken silverman level designer linux mac os ninja novel railgun ryan hughes shuriken source code source port sunstorm interactive tongue-in-cheek video graphics array video game voxel wikiquote