Not bad, but I think it could be better. Rated based on the demo.

For a map of this size, I think it is criminal that there are only two scenes. Although I considering the size of this game and that it is an early version, I believe that its minimal H-scenes could be excused. The gameplay is understandable, although I think the map could provide more nuances to it and make it more interesting; also, I think the character should have a second-stage sprint mechanic because this place is huge. 

However, I think the models looks pretty good! Props to the artist behind the model because they look amazing! 

Not much else to say. For a demo, there is quite a bit to do, but not much else if you ignore the fat. I am interested to see what the final product is like, because a 3D stealth-porn game is something that I never thought I'd see.