A nice start. The colony building sim seems to be quite popular thiese days but with your 3 dimensional approach I believe your game could somehow find its place.
At the moment it's quite a struggle to place the buildings in three dimensions. I'd like at least to see the connecting conduit as a blueprint when trying to place the building because I tend to misplace them quite often. Moving the view can get quite sluggish also, maybe we could use an option to lock it on a building and spin around it, so we will always have our colony in sight.
I wasn't able to complete the third objective in the first mission, having place almost one of every building before increase of population (also beware that the building to place is called "mining bay" when there is no building of a such name).
Deleting building let the conduits in place, which prevents from building another one this spot later on.
I hope you'll manage to grow your project where you'd like, I'll probably check the changes on later versions.