I have to say, I love your bassline. The way it flows into the next repetition is flawless. You hit the nail on the head with the word fluid. The song itself is simple, and nearly pulls that off for the entire song. But I just can't listen to the entire thing without losing focus at one point, which to me makes this a very good ambient song, because the composition itself is simple and deep but it's hook is just a tad shy of flawless. With the right game/movie to focus on, I'd imagine this would make an incredibly rich background sound.
And as a side note, the plucked strings were a nice touch. At least, I think they were strings. At about 1:01.
This was a great song, and the planning of this really shines through the majority of other songs I've heard. Great job mate.