I didn't think the green sky was a great plot choice. When I saw it, my first thought was that it look exactly like an aurora borealis. Im pretty sure the northern lights are visible in at least some parts of Siberia where this show is supposed to take place.
I'm leaning more to all of these characters being not exactly what they seem. It became pretty clear that Annie has been a victim of physical and/or sexual abuse in the past. Nikko is way over the top alpha male and I think he has his own agenda. We've already seen that Johnny and Carolina are not what we thought at first. I also like Irene, but I thought her expertise with that bow was somewhat suspect. The older, heavyset guy (whose name escapes me at the moment) has clear anger issues that must have some significance. Don't know about Esther and Miljan; both have seemed just vile from the beginning.
I'm going to put the following in spoiler tags because I think it's highly significant and seems to contradict some of what I wrote above.
Click to see Spoiler:The cast list at imdb.com lists each player and the number of episodes they appear in. Sabina is listed as appearing in 12 episodes. Seven other characters are listed as being in 6 episodes, three others are in 4, the host, Jonathan, is shown as 3, and Victoria and George are in two. If this is correct, it seems strange that Sabina would be carrying the show alone for 6 episodes, but she has seemed to be the one in the know from the beginning. If anyone wants to know how long each character is supposed to be around, I'll post another spoiler.