To be honest, I originally made this game just for fun, so I built it using plain HTML and JavaScript, no game engine involved. At some point I thought, why not upload it to itch.io just for fun, and to my surprise, it started getting a fair bit of attention.
Looking back, I kind of regret not using a proper game engine from the start, since the current setup has a lot of limitations and performance issues. So yeah, I wouldn't really recommend building a full game with just HTML and JavaScript. It's meant to build websites and web apps.
If you’re interested in game dev, I'd suggest starting with something like Unity or Godot. Both are great beginner-friendly options, and I'd say they're around a 3/10 in terms of difficulty for making a simple game.