If you want to save three dollars, you should buy it now rather than later, because the price is about to be raised.
Anyway, The Stanley Parable. How do I review a game like this? It was enjoyable, for the most part. Pretty funny, too - again, for the most part. The narrator is usually best in small doses, one or two lines delivered to make fun of you or to sarcastically comment on the state of the story. Those are good. When he starts with a monologue, though, it's usually to either a) drag a joke on far too long and suck any and all humor out of it, or b) deliver a condescending, pseudo-philosophical lecture about the futility of choice and the linear nature of video games that sounds like it's coming from the author himself, not the character. Both of those are very annoying.
In short, I guess you could say that the writing is hit or miss. When it works, it works very well. When it doesn't, it falls flat on its face. Not a lot of middle ground.