You are Jebediah B Spookerton, you have just graduated at the top of the class in frightology.
you managed to get a job at the big scary dungeon as a dungeon designer, your job requires you to design the dungeon layouts and monsters to cater to the fears and weaknesses of any adventuring party that stumbles into your realm.
Skullking's game play is very much like a tower defense or base defense game, using your superior skeleton mind you must develop the perfect dungeon to frighten and maybe even kill your foes, if you prove you are a capeable dungeon designer you can get promoted to bigger dungeons and have access to more traps and more monsters!
every adventurer that comes through your dungeon will have their own fears and weak points that you can find and exploit to prevent them from reaching the treasure that lies at the end!