If you want to learn to create relatively simple online games using Javascript, then the HTML5 Game From Scratch Step By Step Learning JavaScript course is a great place to start.

Could you build an online game using just HTML, CSS and JavaScript? Absolutely! And this book might just help you make that happen. The starting point of Build an HTML5 Game: A Developer’s Guide ...

Then, you'll move into courses that let you build interactive games using JavaScript, so you can code and apply Game Logic from scratch.

You'll start by learning HTML5 Canvas and creating Canvas-based games like Pong, Catcher, Bubble Popper, and more. It's an easy way to absorb everything you need to know, while having some fun ...

Though Game Builder does allow you to "live-code" your game using JavaScript if you have the knowledge to do so, it's been designed with the average user in mind.