Wow this is so interesting idea! I've not yet tried to make my own video, but watched several interactive videos from the website. I really like the concept, but one thing it may need to be improved is about the way of playing reply videos. I have to keep clicking the pin buttons to see the replies, and many times the video get rewinded or forwarded.
Why don't you make a little button saying "auto play"? If so, the video will play automatically all the reply videos together so that I don't need to be bothered to keep clicking the pin icons.
Anyway I love the concept and can see great fit with video creators!
RE: Mosaeek - Make video response on top of any video