The HTML demo actually works now!

What it says on the tin! Though there is still one bug for the HTML demo: losing focus from the game disables keyboard input! The entire demo can be played with the mouse, though!

EDIT: The WASM exporter for GameMaker is still new - if you accidentally click outside of the game onto part of the webpage, keyboard input will be disabled! To fix this, go to a different tab, then come back on the one with the game running!