Weird. I'll need some more info so I can troubleshoot:
Are you playing the browser build or the Windows build?
If you're playing the browser build, what browser are you using? Works fine for me on the latest versions of Chrome, Firefox, and Microsoft Edge (tested all three just now)
If you're playing the Windows build, are you playing it on Windows or are you emulating it via third-party software (e.g. WINE) on Mac or Linux?