Instructions
Navigate to the VBA website and check for the latest version of the software (see link in Resources). If there is a newer version available, click on the "Download" link next to the operating system and language version of your choice. Right-click the downloaded file and take the "Extract All" option to unzip the contents of the archive.
Start VBA then click "File," "Open" and choose "Metroid Fusion" from the list. Wait while the game loads and takes you to the title screen. "Metroid Fusion" is not included with the software and is illegal to posses if you do not own the original Gameboy Advance cartridge.
Click "Cheats" then "Cheats List" to get a pop-up window where the cheats can be entered. Click "Gameshark" to get another window where the Gameshark codes can be entered.
Type a description for the cheat in the "Description" box and the actual cheat in the "code" box. Click "OK" to add it to the list of cheats. Click the checkbox next to the code description to enable or disable the cheat. Visit sites like CHEATBOT to get the full list of "Metroid Fusion" Gameshark codes (see link in Resources).