I watched the trailer but couldn't really get a sense for what would make this game unique amongst other settlement building games. I like the presentation, music etc. but can't see how this is different to something like Banished, for example?

There are similarities, but there are also differences.
For example, resources don't run out. You paint a residental zone and the people will build houses there and upgrade them. You have monuments that you can create by sticking parts together. There are soldiers and military campaigns.