You've probably already considered this, but I think demos and completed games should have different rating criteria. A demo should be expected to have some bugs or flaws while a finished game should be polished throughout.
It might be good advice to play the game a little before making a video of it. On the one hand, the viewer won't be able to see or hear your very first reaction, but on the other hand, I've seen some YouTubers fumble around the game/interface not knowing what to do which results in a lot of silence or assumptions. This can inadvertently reflect poorly on the developer when (sometimes) all that is needed is just a little more time getting familiarized with the game. If you play a little ahead of time I think it can give you better commentary for the actual video.