Yeah, the Electron wrapper would be a good idea. The custom sounds idea would require some more work, since the Sega Master System can't play digitized sounds without interrupting the gameplay, though it could be possible to ask the user to provide alternate, SMS-compatible sound effects.
Viewing post in Pocket Platformer Exporter comments
Yeah. Also, I made my first pull request today. It was to correct a capitalization error probably caused by either VSCode or GitHub. Either way, the GitHub version should work offline now.
https://github.com/l0bster2/pocket-platformer/