Heyo! My girlfriend checked your game out (first game in the vid). Although she wasn't sure if there was another ending if you don't grab the knife.
Woah I never thought that my game would be featured on a YouTube video! Thank you!
As for your question, you can still get both endings whether you pick up the knife or not. It's just a matter of whether the ghost will choose revenge or let go.
Anyways, thank you for this feedback and I will use it to improve my future games.