The web player doesn't seem to respond to keyboard inputs. Space, for example, just scrolls the page.
Viewing post in The Great Machine Armada comments
It might be related to local storage or cookies—I discovered that Chrome on my shared computer seemed to be blocking local storage, causing crashes with other games. I can’t get on a computer to verify at the moment, though.
Edit: Yep, it worked when I tested it in Firefox, so I think that was the issue.