Folks,
I was reading
this blog over at Android Central, and it explains how Google has eased up on the guidelines for getting in to the Daydream store with your Daydream app. Some of us have already discovered there ARE Daydream apps in Google Play that are NOT shown in the carousel of available apps within the store ON the device itself. BUT they work perfectly fine, and they DO become selectable on your Daydream once you install them on your Pixel (or other Daydream compatible phone)
I just wanted to give everyone a heads up on this. Start checking your Daydreams!