Feedback from MediaMike on Thriller Opening

My group and I had an interesting conversation with the Media teacher, Mike. We described everything about our idea, and he then replied with some feedback. He really liked our idea; however, he found that the idea was basically a 10 minute short film, instead of an opening sequence. He advised us to take the idea and make a short film out of it in our free time, and only use it as inspiration for our final opening sequence idea. My group and I are now very worried about how much of a serious re-think we are going to need in order to come up with a new idea that matches the quality and creativity of our original idea. If it was entirely my choice, I would prefer to go back to my original idea of the man burying a teenage body. However, I am in a group, so I will re-pitch it to them, discuss some of their ideas and hopefully come up with a finalised idea.