Result: You will have a fully playable tactical game with English menus, but with Japanese story text after the prologue.
If you encounter issues, the following communities are your best resources: gundam seed destiny gba english patch
The remains a holy grail for some and a work-in-progress for others. While a perfect, polished "official-style" translation may still be a community goal, the game is fully playable through a combination of menu patches and modern translation tools. Result: You will have a fully playable tactical
This left Western fans with three options: gundam seed destiny gba english patch