Hello Prairysurf,
We see you have some questions regarding the Just Dance Now game on your Apple TV. We can help get that headed in the right direction.
Are you currently able to use the Siri Remote to control the Apple TV without problems, outside of the game? If so, that helps to confirm whether the remote itself is working well or not.
For questions specific to the game, it would be best to reach out to the developer of the game. We were able to help locate their support page here: Just Dance Now Apple TV Support | Official Ubisoft Help
Some general steps to try for technical issues that can come up would included restarting the Apple TV itself: How to turn off or restart your Apple TV
You can also try uninstalling/reinstalling the game: Customize the Apple TV Home Screen
If nothing here helps, you can find a 'Contact us' button to help reach out to the developers of the game for further help in the first link above.
Cheers.