Balloons would fly at different rates and in different directions as the video shows because they would not all be flying at the same height catching the same winds and air pressure is different at different levels too.
I'm not saying I think they are balloons, but the movement would show otherwise in my opinion. I'm no expert so don't take my word for it, go ask an expert.
I don't know what they are. I personally don't think they are 'aliens', but what do I know. I don't have an explanation. All I can say is that it is very strange and I would like to know what they are. If they are 'alien ships' that'd be really cool. They are definitely UFOs as they ARE unidentified and objects that appear to be flying/floating.
Cool video! Thanks for sharing!