Update: Are you using Chrome? Please read this thread.
If you're having "focus" problems where the game seems to stop responding to the keyboard or mouse, try this URL and report back whether things get better, stay the same, or are worse (and what those issues are/were, which web browser you are using, and what operating system):
[link removed, it is enabled for everyone]
Please only report problems related to the above; nothing about performance, house decorations, the Rube, etc.
Thank you for testing!