I personally really think this will be a very big success once it is fully finished. I recommend trying to see if it is possible to get it on consoles as well since it really has a good shot with everything being really really good. I highly recommend looking up marketing and the best of Steam's best practices for graphical images and trailers.
You definitely need music, and if possible a very short animated intro with more sound effects for when someone is eliminated and at the start. Flapping needs something very low volume but there. 100% will get on release.