Can you play any other xbox games on a xbox 360 kinect

The Kinect is just an accessory for the 360. All 360 games will work on any version of the 360.

Xbox 360 Kinect games can only be played with Kinect on Xbox 360 and it would be recognized if you attempt to plug the Kinect Xbox 360 to the Xbox One.

To play the Kinect games released on the Xbox 360, you will have to play them with an Xbox 360 console with the Xbox 360 Kinect Sensor.

The Kinect Sensors are not interchangeable between consoles (you cannot use One Sensor on Xbox 360, nor a 360 Sensor on Xbox One), as both Kinect Sensors have different, proprietary Kinect plugs, and the games are specifically programmed to use the exact Kinect
sensor on the console they were released on.

I don't think any of the Xbox 360 Kinect games can be played on the Xbox One, because the

360 Kinect is not compatible with the Xbox One, but feel free to look the the list of

backwards compatible games anyway.

For example, my cousin plays on the Xbox one s and my brother plays on the original Xbox one. Will I be able to play online with them?

Yes, absolutely. You can also play BC 360 games with users who are still playing on Xbox 360.

All Xbox One games (but not kinect games) will work on on Xbox Series X/S and you can play these games with others even if they haven't yet bought the latest console.