Here is the Class Central page with reviews:
https://www.classcentral.com/course/udacity-interactive-3d-g...
You can search for other courses on class central, though searching for webgl didn't actually find the Udacity course - had to look at related courses for a no longer available Coursera course listing that searching did find.
Edit: Also, Packt's free ebook of the day is currently Learn Three.js, which is a wrapper around webgl. Only available for the next 9 hours or so. If you don't have a packt subscription, you can only read it in a web browser. https://www.packtpub.com/free-learning
Here is the Class Central page with reviews: https://www.classcentral.com/course/udacity-interactive-3d-g... You can search for other courses on class central, though searching for webgl didn't actually find the Udacity course - had to look at related courses for a no longer available Coursera course listing that searching did find.
Edit: Also, Packt's free ebook of the day is currently Learn Three.js, which is a wrapper around webgl. Only available for the next 9 hours or so. If you don't have a packt subscription, you can only read it in a web browser. https://www.packtpub.com/free-learning