I am not sure what the point of the first 5 levels are.

Sure, level 1 shows us how to complete it -- but a big blinking yellow arrow or something to help me see what's what would have been nice. I spent a good 10 seconds just looking around and clicking.

Levels 2-5 just feel like different art assets for a bit, only after playing 6 and going back do I see that i was placing different tiles.

Difficulty

The difficulty ramps up way too quickly from 5 to 6, then 6 to 7.

hope this walkthrough help (it shows some gameplay in lvl 5 6 7)

nope i have no idea how to automate adding population

I feel the same. The game looks amazing but I have no idea what to do.