Deadwax is pretty original and overall flows pretty well. The acting is good and the story is captivating. It's more mystery and thriller than horror.
In my opinion, where it falls short is that it leaves a lot to be desired. It feels rushed. Halfway through I already knew it was going to leave a lot of the stuff very open-ended. While I don't automatically hate the approach of leaving some elements vague and open-ended in a story, I felt Deadwax had too many of these elements.
The soundtracks of the series and the dark atmosphere sprinkled with psychedelic visual effects leave a good taste. I just wish they had extended the series at least by half to close some of the open-ended elements which would have more than likely provided a more fulfilling ending.
Overall though, I recommend it. I'm stuck between a 6 and a 7 so rounding up from 6.5.