Building was part of the sandbox from day one, but the concept was quickly sidelined to focus on getting the actual game in a functional state.
I wanted to have more crafting mechanics and stuff where you'd be incentivized to hold up a fort somewhere, also segments of the game where you'd be given an objective to defend points on the map, just didn't get the time to flesh it out.
I don't think I'll do too much to change how the game plays other than fixing bugs and cleaning things up, but if I can give building a bigger purpose than setting up chokepoints/defense and traversal, I will.
I'm glad you enjoyed the game!