On ChromeOS, I got stuck on the very first screen:

I can either enter a Project or a URL to edit. Typing text in either place does nothing interesting. "Enter" does nothing.

Clicking around, I can't find any way to make a new window. All I want to do is see your editor and start playing with it. I don't even really want to edit a file yet. No obvious way to make any of that happen.

The first window is too small. The note about how to edit remotely requires scrolling, but it isn't obvious that the page needs to be scrolled.