Dungeon build/defense, something like Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ and/or Evil God Average, maybe?
Premium? N o t a p r o b l e m *checks* it's there. Go and Google it~ from chap 1xx to 845. All free.
A Demon Lord’s Tale: Dungeons, Monster Girls, and Heartwarming Bliss - Dungeon building/defense...and outside world as well! Hachinan tte, Sore wa Nai Deshou! - It's more territory building than kingdom building....but it does have a lot of politics involved. So... Hisshou Dungeon Unei Houhou - This is dungeon management/defense...but it does have some themes that you might not like. That's up to your preferences, though. I Became the Demon Lord and my Territory is an Uninhabited Island - It takes awhile to get to the "kingdom building" part, where he has his own territory. It does happen, though. Isekai Nonbiri Nouka - This is more village creation and village management than kingdom management...but it might be up your alley. It's quite slow-paced, though. Lazy Dungeon Master - Dungeon management and defense. Otherworld Nation Founding Chronicles - Kingdom improvement/building. The Legendary Moonlight Sculptor - It eventually starts including territory/kingdom building in it...it takes awhile though...and it's not really ever a huge focus on it. It's also a VRMMO and not an "actual real world" thing he's doing. The Story of Hero Among Heroes ~The Founding Chronicles of Arestia~ - It starts out as a territory building thing, and goes into a kingdom building thing later (though it's made clear pretty early on that a kingdom sort of thing is basically his plan from the getgo) Hope these help~ ^^
There is no Epic Loot here, Only Puns. - silly and cute, but can be sappy and sad at times as the MC tries to cope with being a dungeon. Lots of eccentric villagers. Dungeon Robotics - straight up adventure type story. The dungeon MC used to be an AI and robotics super genius from a high tech world.
Erm...it's difficult to recommend something you didn't know about...or rather, forgot about cause you weren't sure you'd even enjoy it. XD