You've really got things backwards... itch.io /does not require a launcher/. You don't need to download some other thing to connect your game. If you use 'add non steam game' from your library, it will behave exactly like a steam game... except that you won't lose it if you lose access to your account, you can play it offline indefinitely, or even put it on a usb drive to play it on any computer you wish. There is no DRM, be free and enjoy your game lol