Is it worth 15 bucks? No. Is it as good as many make it out to be? Of course not.
Remove the distinct visuals and Journey becomes a simple platformer. Did I say simple? No, that is giving too much credit to it - Journey is the simplest and the easiest platformer ever. And the shortest one at that.
Now about the music - I'm a fan of ambient and instrumental music, as diverse as the music of these genres can get. So you might guess that I've heard s lot of cds of these genres from the best artists of these genres. Correct. Now, to call the music of Journey as great or even good, ARE YOU KIDDING ME. Please.
It's like, people have been living in caves playing call of duty or whatever and now they finally starting to crawl out of their caves and coming to senses. Hello? You want to experience a truly great journey? Pick Okami. Hell, Okami isn't a good example actually because it's worth like zillion Journeys. Pick whatever good game and you will realize that Journey has nothing on it.