Hello. Assistant Developer here to comment on library usage.
Revolvum was made using Pygame-ce, which is a fork of Pygame (a Python library used for the development of multimedia applications such as video games).
From my understanding, Pygame indirectly utilizes SDL in the sense that it is essentially a Python wrapper of SDL. However, Ray was not used. As far as I know, Ray is more commonly used for parallel computing or Artificial Intelligence/Machine Learning applications as opposed to a standard game loop as in the case of Revolvum.
Thank you for your comment, I hope this clears some things up.
P.S.: The resolution issue you mentioned will be investigated and addressed in future Ghastly Games releases.