Golden Sun is the first installment of a series of RPG games developed by Camelot Software Planning and published by Nintendo. It was released in November 2001 for the GBA, with a sequel, Golden Sun: The Lost Age, in 2003.
Golden Sun underwent a development cycle of between twelve and eighteen months by Camelot, which is considered quite a long period of time for the development of a handheld video game, and was described as a “testament” to the positive results a long development cycle can bring to a game. It was shown in early, playable form at the Nintendo Spaceworld Expo in Japan on August 2000. North American previewers received the game a few weeks before the release, and IGN noted that the experience of developing Shining Force for Sega helped Camelot develop a gripping RPG for the handheld.
Originally, Camelot planned to create a single title instead of a series, and in the extremely early stages of their project they had created a game design document for the one Golden Sun game to be on the Nintendo 64 console. When it became apparent the N64 was on its way out because the Nintendo Gamecube was coming in, Camelot shifted their focus to making a game on the handheld Game Boy Advance. [Info from Wikipedia]
In these old screens we can see a beta version of Golden Sun, with differences in the graphic style, in the characters design and in some weird places. The Kusanagi is a Light Blade that is found in the Debug Menu of the original Golden Sun. This weapon is impossible to access during normal play and can only be seen using a hacking device. Ironically, this weapon’s graphic is officially used in Golden Sun: The Lost Age for the Light Blade artifact Masamune. If it had been in the original game it would have been the most powerful Light Blade surpassing even the Kikuichimonji. You can find more info at The Adepts of Weyard website and at GoldenSun Wikia!
Thanks to Robert Seddon for these links!