Is it possible to view GBA game files?

[Fadsy]

I don't want to edit the files, I just want to view them. I want to try and make an HD sort-of remake of Bionicle Heroes on the GBA. I really love the original game so I want to see what I can do to make it better.

 

[Kwyjor]

Do you mean you want to view graphics? The process is the same as almost any other game: you open the ROM in a tile editor (like Tile Molester) and hope that the graphics are stored in a recognizable fashion. The GBA did not typically use "files" of any sort within the ROM; everything was usually stored as a big binary blob.

Compression was fairly common in GBA games since it had built-in BIOS decompression routines. Tools exist to decompress data in that specific format, such as https://www.romhacking.net/utilities/431/ .

But you can't expect to view levels maps or anything particularly complex, since developers were never required to store that data in a consistent format and you would have to painstakingly reverse-engineer the data format for each individual game before you would be able to view anything like that outside of the game.