Kessrand: The Last Warden

Dungeon defense, from the side of good.
You are not the overlord with a dungeon to protect or a living Dungeon. You are the last Warden of a fallen Kingdom, and an army of the cursed has come into the mountain to hunt you down. Between waves you dig a warren of tunnels and traps. When the wave breaks in, you are down there with them -- fighting, running, and leading them into everything you built.
Meanwhile, the Heir to the throne musters a desperate gamble to reclaim the Kingdom. Do your duty and keep the enemies distracted long enough for him to succeed!
Dig the trap. Be the bait.
Carve tunnels through solid rock and line them with spikes, fire, ice, pits and burning oil. Then keep moving. You are the one thing they are hunting, so you decide where they go.
They cannot see through stone. Slip out of sight round a corner and they head for where they last saw you -- which is where you left the trap.
The mountain changes under you
You are not the only one digging. Enemy tunnels burrow toward you through the rock. You are warned when one starts, but not where it will come out -- until it breaks into your tunnels and create a second invasion path.
Free the cursed
The Ashen Host were ordinary people once, before a curse twisted them. Bring them down inside a purification circle and the fallen can be freed to fight at your side. Place allies, give them orders, and turn the Host's numbers against it.
What waits inside
A ten-mountain campaign, with a new cave to dig every time you play, and bosses along the way.
Three ways to fight. Start as the mage, then earn the warrior and the archer. Choose from 40+ abilities and 10+ passives as you fight on.
A horde that needs planning to defeat. 15+ kinds of enemies, each with its own strengths and weaknesses and 10+ Bosses with their own powers!
Progress you keep.
Every run, won or lost, earns Essence for new classes, abilities and permanent upgrades.
After the campaign, harder Ascension tiers and an Endless descent that goes on until you fall.