Is this a good idea for a game script?

You arrive as a member of this universe's paranormal department in a city ruled by a psychic demon and its hybrid children, hidden from the public with mind control. Your mission is to break into the city center and steal all of their data to bring back to your government.

The center is the tutorial level, as the agent uses stealth and knife skills to move through the building. At the end, the agent is forced to hide in a sterile room with a pale, young woman strapped to a medical chair, her legs bound open but tastefully concealed(I'm not that much of a pervert). The agent unstraps her and she snaps awake, grabs his head, and stares into his eyes with mutated, black eyes. The both of them experience extreme pain and pass out.

The woman wakes up with the agent's memories for a few seconds, before her brain censors all but the useful data. She escapes in her confusion, stopped by a mutant with the ability to become psychically invisible to anyone not specifically looking at it. After a fight in which she utilizes her new knife skills, performed with a jagged scrap of metal, she touches its head and takes its power, escaping into the city.

After a series of missions based around remaining safe and revealing the history of the city, she has to return to the center to rescue the agent, confronting her father, though only surviving due to something set up earlier in the game(I haven't figured it out yet.)

So? Thoughts?

How would you pitch your game in one sentence?

^ I'm not sure one sentence would do this premise justice. (But one sentence only pitches and their merits/pitfalls is for another topic.)

Dishonored with psychic powers inspired by lovecraft-style aliens in present day/very near future.

I've wanted to do a stealth assassin story and I had a character idea bouncing around for a long time. It was really cemented when I saw some fanart of Emily in Corvo's gear.

A lot of the rest of the concept comes from Call of C'thulu, where a god is hybrid...ed and the cult controls the town.

But yeah; climbing, stealth based combat, supernatural themes, that's why I originally thought of Dishonored.

Right now, I'm working mainly on balancing enemy design with the powers to make it interesting instead of frustrating, give the player lots of choices.