Other things I appreciated -- based on the first novel of a trilogy, it would have been in keeping with the times to set up the second and third books for future
It's a shame that in a world of endless comic-book spin-offs (many of which I enjoy! honestly!) a truly great, thoughtful, intentionally slow-paced, and relatively low-budget sci-fi flick literally can't make any money.
If you enjoyed the film, do yourself a favor and read the books which are a lot different in terms of characters and plot, but pretty similar in mood and themes.