Have viewer display/project correctly a pano that is neither a cylinder nor a full sphere
I imagine that the viewer technology has access to the number of pixels horizontaly, then it knows how many pixels high it can use in the viewport, thus showing the pano without distortion. Then of course it should be possible to tilt navigate the pano.
This pano consists of a horizontal capture ring and an upper capture ring. It has been stitched with Microsoft ICE with a spherical projection. So, it is neither cylindrical, nor full spherical. As one can see projection is distorted. I feel this is an issue of the viewer technology.
Your panorama is considered a cylindrical panorama. Spherical panoramas have to have 2:1 ratio.
The panorama seems to be distorted because its horizon is not on the middle of the image. So that makes it is not level.
Joscelin Trouwborst commented