"The GIF file is an image, so it will only play the slides one after another. You can simulate animations by having short timings on your slides. You can learn more about the current GIF export on this page.
We know some of our users are interested in fully animated GIF files so we're looking into a solution that will allow our users to export exactly that from the banners created. When researching this we have two things in mind: The animation should be as flawless as the html5 output and the file size should comply with the standard advertising requirements. Send us an email here we'll let you know as soon as it's ready. "
We do have a fully animated gif version, you can find more info here.