You play Detective Diamond, or DD for short, and together with his overly cutesy blob/rabbit sidekick, you... I'm not sure what you do. At all. I do know that after an amazingly long comic-bookstyle intro, you start out the game being attacked by some kind of monstrous housekeeper. After vanquishing the Hell Maid, I launched into an overworld, where I ran into a cute blonde reporter who apparently killed me. There's a brief plot synopsis over at Kotaku