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.
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.
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.
Anyway, it's instant tea, you get a packet of instant tea and powdered milk and something related to wheat, I don't know, a separate packet of sugar, and a tiny cup of coconut jello cubes in syrup. To add to the tea, or to eat separately, not sure. The instructions are in Chinese.