Pluses- the mystery and suspense, the sound effects and sound tracking, the camera work, some good thoughtful dialogue and the leads acting which holds together the movie
Minuses- some wooden support acting, and the plot doesn't entirely make sense how it ends.
Overall, work a watch if you don't mind more amateur indie sci-fi and don't expect too much, but if you expect something Hollywood polished, action driven, special fx driven or mindbendingly crafted, give it a miss.
