So check this shit out: I'm looking for nothing less than Atlantis itself. I am a deep-sea explorer in a personal submarine that shoots lasers (no, I'm not kidding--I think the corporation that funds my research must be shopping at the same store as the EVIL POWER MASTER).
Much like The Jewels of Nabooti, there are several what I like to call chickenshit endings. They're sensible enough: "A giant squid has just destroyed your submarine. Do you A) fire a harpoon that has roughly the ratio of mass to the monster as a toothpick does to you, or B) hop the next friendly dolphin the fuck out of there?" "You are suffering from the bends. Do you A) put your helmet back on and give it another go that afternoon, or B) sit the expedition out, go to a waterpark instead?"
The adventure is already gasp-worthy before you even start to explore Atlantis itself (what with the bends and squid and man-eating fish and all). Down in the sunken ruin, you can explore the remains of ancient Greek triremes and explore
Although the people of Atlantis seem wary of outsiders at first, it becomes clear, through several story options, that they are in fact looking to enjoy your company in some form or other. I was given the choice at one point either to undergo an operation that would allow me to breathe underwater with a brand new set of gills or be imprisoned in the Atlantean Zoo. Nope, that's not canon.
In one story arc, I was commissioned by some peasants to have a chat with their cruel king. And this was actually a quite satisfying arc in its branching paths: I could talk to the king, find him charming, and become one of his advisors. I could threaten the king with insurrection, which would be interrupted by the discovery of leaks in the city walls caused by a volcano; at this point, I could then either join in the effort to shore up the walls, at considerable danger to my person, or hop back in the sub and get out amid the chaos.
Thank you, chaos.