Thanks for the kind words, everyone 
@ order66: I thought so as well, and I included the last video posted above in the initial marketplace submission. I was told that I couldn’t use that video because I used assets from the Couch Knight demo, and that the only assets I could include from Epic were the ones in the starter content (their answer was a bit unclear, but that’s how I understood it). My submission was significantly delayed because of this, and I agree With you that Epic’s guidlines seem to suggest that assets from the free samples are fair game. They should probably update the submission guidlines to clarify.