To save people a lot of grief with Dungeon of Punishment.

On looping floors.
Take the first left, jump gap and go straight into room with chests, grab key off the wall.
Exit that room on the right into room with gargoyle and open door with key.

There's also lots of hidden scenes underground in the looping rooms, look down in the moving platforms room and you'll see a ledge that can be jumped down onto that leads to a lot of goblin scenes.