I doubt you could produce screenshots that fast, and filesize would very quickly become a big problem. Maybe it's possible - I don't want to be a buzzkill - but I really don't think that's the method you want to pursue. You'd probably end up with low picture quality, low frame-rate video.

If you can just implement a system that stores the user's actions during the recording phase (as I mentioned above) you get a small, portable text file that can easily be shared between people and played at different levels of graphic quality, etc.