I've run Morrow Project meets Call of Cthulhu before, and had a lot of fun with it. I ran it as a convention game with no prior warning and the players had a good time fighting cultists and staving off the shuggoth.
The stories on this video
https://www.youtube.com/watch?v=nhkgXOUDetc&t=1425s would make a really great start for a Morrow Project horror supernatural horror camapign or game.
I may never go hiking again. And what is with all the staircases?