The Game Boy Advance's buttons are mapped as follows:

For legal reasons, GBA.js is presented without any included games. Please click Select below to choose a Game Boy Advance game image from your hard drive that you'd like to play. The games must be uncompressed, so unzip them as needed.

Please note that this is a beta and there might be compatibility problems. More information and a link to a compatibility table can be found on the sidebar. If you're feeling daring, please submit problem reports to the GitHub page.