One would expect the unused sprites from the DS version to be here.
Gyakuten Saiban (Turnabout Trial) is a Japan-exclusive game where you play as defense attorney Ryūichi Naruhodō to defend innocent defendants. Assuming you aren't Japanese, you probably know it because of its internationally-released remake for the Nintendo DS, Phoenix Wright: Ace Attorney.
The game contains an unused piece of music. It sounds somewhat like the credits music for the fourth case; perhaps it was an early version of said track. It also exists in the DS remake.
©CAPCOM CO.,LTD.2001 ALL RIGHTS RESERVED.
There are unused graphics for a demo version or mode. Near-identical graphics were used in the flash demo that was featured on the game's website and a screen similar to the ending one here can be found unused in the DS version.
Save Data Version Info
The game contains some version info at 0x18A3C in the ROM. It is used at the start of the save data and doesn't differ between versions. It is unknown if the version info is for the save format or the game.
2001 CAPCOM GBA GYAKUTEN-SAIBAN 06/15 Ver 1.000-
|The Ace Attorney series|
|Game Boy Advance||Gyakuten Saiban|
|Nintendo DS||Phoenix Wright: Ace Attorney • Justice for All • Trials and Tribulations • Apollo Justice: Ace Attorney • Ace Attorney Investigations: Miles Edgeworth • Gyakuten Kenji 2|
|Nintendo 3DS||Professor Layton vs. Phoenix Wright: Ace Attorney • Dual Destinies • Trilogy • Dai Gyakuten Saiban • Spirit of Justice|
|iOS||Phoenix Wright: Ace Attorney Trilogy HD|
|Nintendo DS||Ghost Trick: Phantom Detective|