Congratulations on your first 3D game! :)
Visually and sound-wise, there’s absolutely nothing to complain about. I think the fact that it doesn't just end after "Floor 10" is a great creative touch. I also really like the simple solution with the two buttons in the elevator. Usually, in these types of games, you have to run all the way to the end or back, and if you make the wrong choice, you're frustrated to find yourself back at "0." In your version, you only drop back one floor, which I think is a good move!
My only point of criticism is that in these "Exit 8" style games, I’m used to the first floor always being the "clean" one without any anomalies. Other than that, it’s two thumbs up from me! Keep it up!