Super Mario clouds is the background of Mario Brothers that Cory Arcangel erased the characters, obstacles,monsters etc. Only a blue sky with white clouds are moving from right to left. It is not narrative and does not show any challenges to viewers.
I think Super Mario clouds is art but not a game. It shows a scene which is the sky in the real world. This artwork is the background of the game, so we can regard it as 'moving' wallpaper that classified as decorative arts. However, it is not a game because it is not narrative which means no story and no challenges to players.