I approached Floatpoint as a story, rather than a puzzle or a game, and it met all my expectations and more. I'm fairly sure that even if I'd been reading it as a linear, fixed narrative, I'd still have enjoyed it; but the fact that I could influence the ending (towards what I felt was the right thing to do) gave it an extra dimension.
For context, I'm a great fan of short stories, and of the kind of science fiction that focuses on how the snazzy futuristic situations affect the people who find themselves in them. Floatpoint hit all my buttons. I just wish my memory was less vivid, so I could play it again sooner and try for a different goal!
(I should also note that in contrast to Valzi's review as of 27 October 2007, I didn't encounter any bugs.)