The Thirteenth Floor was a really enjoyable (and sometimes frustrating) game. The real takeaway for me was the gameplay, albeit how simple it was, mainly because it didn't "spoon-feed" you what to do. Yes, it does give you easy clues on where to go next and what to do, (particularly finding scattered notes throughout the floor that contain door codes), but some of the objectives allow players to critically think. The use of critical thinking wasn't even much (maybe I wasn't in the best mental shape when I played because it took me a while to figure out what to do next on some parts), but the point is there are some parts that don't flat-out tell you what to do. You're free to think on your own on some parts of the game about what you're supposed to do next to progress, rather than the game telling you what to do. The tension this element creates alone was satisfying, and coupled with the creepy, dark environment of the hotel floor, the game will have you on edge in some parts.
I was actually expecting it to be more creepy than it turned out to be, but it was satisfying enough to be entertaining. If anything made it spooky aside from the ghost and the dark environment, it was the mere style of the graphics. I think the use of PS-style graphics in indie games has become a staple in the horror genre that the look of these graphics immediately gives players that creepy feeling.
A great added feature are the Easter eggs scattered throughout the game as an homage to their inspiration. To the developer: Was the stinky bucket an easter egg of the vomit bucket from the movie Se7en? The movie was the first thing I thought of when I saw it, and now I'm dying to know if I'm right or wrong.
Anyway, I really loved this game. The graphics, mechanics, gameplay, story (though very cliche), and delivery were all great.
EDIT: Comp-3 reached out to me via Twitter informing me that the stinky bucket was not an homage to Se7en. Still, it's a great connection, though.