[dvdkhlng]

I'd suggest TIC-80 [1] as an intermediate step from Snap! to larger IDEs. TIC-80 documentation [2] is a little thin, but overall it's a very pragmatic integrated development environment that combines sound, sprite, map and code-editor into one very simple IDE environment (no debugger, though, only rudimentary logging).

You have a choice between multiple script languages (Lua, Javascript and more). The run-time library [3] only has a handful of simple functions but is feature-complete nonetheless (plus there is some address-based peek/poke API to do more advanced, low-level stuff).

I'd imagine learning javascript programming by starting game-development in TIC-80 to be much more straight-forward than attempting to wrestle with the complexities of HTML5+CSS+javascript+tooling for in-browser programming.

[1] https://tic80.com/

[2] https://github.com/nesbox/TIC-80/wiki

[3] https://github.com/nesbox/TIC-80/wiki#special-functions