Well composed, not a bad listen, just not my taste. When I think of Portal I look at the future and technology. This creates a bond between the way "Still Alive" was created and the idea of Portal. In my mind such a soothing and up beat style such as Jazz doesn't fit the song. The idea of a giant robot that controls your movements through a lab doesn't say Jazz to me.
Again, great piece... just an unexpected style and not as filled with synergy to the real game.