I actually use a game Engine called Godot. Godot (or any other game Engine) is kind of like Scratch but with way more features you can use to make bigger and better games. Once you create a game on Godot, you can export the game AS an html5 game (you can also export it as a Windows game, Mac game, etc.). There are tutorials out there that can help you get started learning Godot and the learning process would be similar to Scratch just with more features to learn. Also, you wouldn't have to use Godot, you could choose a different game Engine such as Unity or Unreal Engine. I would suggest doing a little research to see which game Engine you should use based on what kinds of games you want to make. Looking at your jam submission, I think you have what it takes to start learning a bigger game Engine if you have the patience. I'm glad you enjoyed my game, and I wish you the best of luck if you start learning a new game Engine!