Drunken Robot Pornography has a unique concept to go along with its memorable title. You take control of Reuben Mastumoto, who is having a real bad day. He accidentally made his robot bartender, Tim, self-aware and presumably being slightly freaked out by this, Tim burned down Reuben's bar and stole all the other robot staff members.
Now Reuben has to defend Boston from Tim and the awesome titans he's created from the former bar staff. The premise of Drunken Robot Pornography is absurd but it's the basis of a solid game that blends the massive bosses of a bullet-hell shmup and the tight first-person shooter arenas of something like Quake III.