2 Replies
Judy Nollet

That Play button shows up if the first slide has any audio or video. That's because modern browsers disable auto-playing such media files. So the only way to get rid of it is to start with a slide that doesn't include audio or video, but that does require the user to click something to advance. (The click tells the browser that the user does want to play the media.) 

There's more info about this here: 

https://articulate.com/support/article/Storyline-and-Studio-Videos-Don-t-Autoplay-When-Slides-Advance-Automatically