My kids all reject the current interface. They loved the interface it had a few years back. In case you need more info to identify what I refer to, I'll describe it.

I'm pretty sure there was nothing but math. Each topic was represented by a circle, and each circle was connected to prerequisites. Kids would earn points in a simple way. Kids would also earn various astronomy-related badges.

The new system simply doesn't motivate any of my kids. It isn't a change in my kids; I have enough kids (twelve) to average that out. Kids who liked Khan Academy before now don't, complaining about the interface. Younger siblings, now the age at which the older siblings liked Khan Academy, also don't like it.

Also, a completely different matter: Last time I checked, which was some time ago, the video required YouTube. If I need to block YouTube, the video can't play. Hopefully you found a solution for that long ago.