It doesn't leave files in the "AppData" folder. Once you close the tab or remove your USB, the game is gone.
Moving from 1.8 to 1.15 isn’t just about a version number; it changes the gameplay loop significantly:
To use Eaglercraft 1.15 Portable, players typically look for "Eaglercraft Github" repositories or community-hosted mirrors. Locate a trusted HTML5 build of Eaglercraft 1.15.