Heroes Suck

You are the Keeper. A dwarf named Kaelviir bought a mountain, opened a dungeon under it, and hired you to handle the part where the people who walk in do not walk out. The heroes call it a daily. Kaelviir calls it trespassing. You call it a floor plan.
Nothing in here simply falls over. Every trap fires into a live physics sim, so heroes get launched, set on fire, and bowled into whoever was standing behind them. They take it about as well as you would expect. "Ow! My knee!" "This is going in my review." "Tell my guild I soloed it."
Build the walk
Your treasure sits at the far end. Reaching it is their whole plan. Deciding how long that takes is yours, one tile at a time, and the distance between the door and the gold is where you put everything sharp.
Seven traps, none of them polite
Hidden Spears through the floor. A Pendulum Axe the width of the hall. A Wall Crusher that simply leaves the wall, and takes the front rank with it. Flame Jet, which keeps burning after they run. A Lightning Pylon that arcs into the nearest hero, then jumps from him to the next, and the next, until the charge runs out. Arrow Rain, which is precisely what it sounds like. And the Time Warper, which deals no damage whatsoever. It slows everything inside its radius, which is a polite way of saying it holds them still for the other six.
Five grades apiece, upgrade lines on every one of them, and a Forge back in town that triples the damage of everything you own.
Seven powers, four slots
Throw a crowd across the room. Reset a trap mid-cooldown so it fires twice. Shut off the healer. Strip the buffs they walked in with. Then drop something enormous on whatever is still upright. Seven of them, four slots. Every stage starts by deciding which three you can do without.
Take all of it
Gold, gear, treasure chests, and all the arcane knowledge they will not be needing any more. It piles up fast and it stays yours. Build the Storehouse and it stays yours even on the nights that go badly.
Persistent progression, no resets
Three mastery trees, paid for in knowledge taken off the fallen. Every node you buy and every trap grade you unlock is permanent, and carries into every stage after it. You come back to each fight stronger than you left it, forever, until the heroes are the ones filing complaints.
Rebuild the town they ransacked
A forge, a shop, a scriptorium, a storehouse and a town hall. All upgradeable, all permanent, all of them quietly making your dungeon a worse place to visit. The Town Hall collects taxes while the game is closed, so the valley keeps paying you for a job you are not currently doing.
The campaign ends, the heroes do not
A prologue and four chapters, 45 stages, each with optional challenges for anyone who wants to prove a point. After that, Kaelviir starts posting fake quests to bring more of them in. They accept without reading a word of it, all the way up through Brutal and into Abyss, which is named accurately.
So, the cheese
The Shadow Guild used to be noble. Now it is cornering the world's cheese market on the Guild Master's written order, for reasons nobody will explain, and the Mayor is taking it extremely personally.
Working out why takes the entire campaign. Working out why the Mayor loves cheese this much takes longer. He has been asked. He does not know either.