This may be rare—I hear so often from friends and acquaintances how much they like learning from videos—but I can't be the only one, so:
One of the things that makes me want to keep a site open, or to revisit it, is a focus on text and a lack of autoplaying videos or sound. StackExchangeStack Exchange has been like that, and it keeps pulling me back to revisit it. While I'm glad you're trying to keep this "limited", 15 seconds of animation does not sound "light" to me (personally speaking only!), so keep in mind you might lose a little traffic from the kinds of people that might love these sites.