var links = [
'https://s3.amazonaws.com/Minecraft.Download/launcher/Minecraft.exe',
'https://s3.amazonaws.com/Minecraft.Download/launcher/Minecraft.dmg',
'https://s3.amazonaws.com/Minecraft.Download/launcher/Minecraft.jar'
];
function downloadAll(urls) {
var link = document.createElement('a');
link.setAttribute('download', null);
link.style.display = 'none';
document.body.appendChild(link);
for (var i = 0; i < urls.length; i++) {
link.setAttribute('href', urls[i]);
link.click();
}
document.body.removeChild(link);
}
<button onclick="downloadAll(window.links)">Test me!</button>