Was I the only one who though the ending was really weird? Did I miss something or did we never get an real answer to whom "the dark ones" where? The voice that constantly stopped the action and said all that weird stuff, what was that all about? Just an effect to create a creepy atmosphere perhaps? 
 
Also, I loved the game, but the ending really didn't deliver the "epic-ending" it was building up to, I think. Any thoughts on this?

Nothing will ever live up to your expectations, after all you are a fucking SPACE TURTLE HOLY SHIT. 
 
I ain't played it, but I'm tempted to pick it up.

There's an alternate ending. I'm not entirely sure how to get it as I haven't gone for it yet, but I have a feeling it explains them a tiny bit more. I'm not 100%, though.
 
Plus, it's also based on a book. Assuming it's mentioned there, they may not have wanted to give everything out in the other project.

I got the option for two endings when I got to the final part at the top of the tower. I don't know how it works for people who only got the one ending (missiles wipe out mutants and dark ones?), but I was standing on the top of the tower with my gun after shooting the alien in the weird dream world thingy, and had the option to either let the missile thing play out, or shoot the guidance laser thing off the tower, saving the dark ones as the voice over implies you should do. The guidance system lands beside a dark one standing at the foot of the tower and there's a little bit more conclusion to the story, but not much - you don't really find out any more about the nature of the dark ones or anything like that, you just realise you've done the right thing and Artyom concludes that the visions he was having were the dark ones trying to reach out to humanity. 
 
I personally liked the ending. The atmosphere and creepiness of the game itself was the center point of the game for me, not so much the mystery surrounding the dark ones.

I don't understand why, if the Dark Ones were truly interested in learning and peace, they attempt to KILL ME whenever we come into contact.  Why you gotta be like that?  Maybe if you tried to explain yourselves a little more instead of going for the jugular we wouldn't be attempting to missile your hole in the ground.  I was hoping to learn more after stopping the missiles, but no and to that end the ending was fairly anti-climactic.

@Bane:
They never actually hurt you.Notice that they only stun you in the game.The pretty much madden or kill the others,but you are never attacked by one.I was hoping that Artyom was a link to peace with the Dark Ones.Nukes aren't peace.

I just thought of something... This might be stupid thou. But if there are different endings, maybe at the end, when your running through that labyrinth and those other places you are being chased by what I assume is a "dark one", right?. Instead of running from it, perhaps something different will happen if you run towards it? I will try it out. Again, that might just be stupid...

So, did anyone manage to get the good ending?
 
If so, could you upload your files somewhere? I really want to have them! :D

I really liked the ending! I got the "bad" ending but I like how the game doesn't really represent it like good/bad, and also I was totally aware of what I was doing, if I'd wanted to know more about the dark ones or give them a chance I wouldn't have run away from them constantly in the psychic (or whatever) scenes, I wouldn't have shot that one at the end and I wouldn't have let the nukes land.  
 
But yeah I loved every minute of that game and I'm pretty tempted to jump back in again some time soon!

If you run toward the Dark One in the labyrinth - you die.  I tried it.
 
I've seen a list of about a dozen opportunities throughout the game for you to do a good deed.  If you do the good deed the screen will flash and a sound effect will play.  Since I didn't come across this list until after I beat the game I didn't realize at the time what that flash/sound notification was for, but it happened to me several times as I played.  I didn't take advantage of every opportunity, maybe half of them, and I unlocked the good ending.
 
If you've unlocked the good ending you don't have to end the game that way.  You can choose to go either way and if you reload your game after seeing one you can go the other way and see the other ending without having to play the game again.

I like the bad ending more than the good one. From what I've heard, the book also ends with the bad ending. Either way, great ending to a great game, definitely in my top 3 so far this year.

Here is the alternate ending on Youtube in case anyone still wanted to see it
 

" There's an alternate ending. I'm not entirely sure how to get it as I haven't gone for it yet, but I have a feeling it explains them a tiny bit more. I'm not 100%, though.  Plus, it's also based on a book. Assuming it's mentioned there, they may not have wanted to give everything out in the other project. "

I like the "bad" ending a lot more than the "good" one.  The latter just feels so contrived to me.  Seems like Artyom forgot that the Dark Ones drove a huge amount of people from his home insane just because they can't communicate properly with humans at all.

" I like the bad ending more than the good one. From what I've heard, the book also ends with the bad ending. Either way, great ending to a great game, definitely in my top 3 so far this year. "

" Well I am not going back to do everything again,but damn,was the good ending better.This game seem to have dumped good and evil-If you spare a bullet,you get the achivement "The Realist" not "Evil Bastard".I thought you could save the Dark Ones and I really wanted to,but the game dictated the ending by my actions.Not giving a bullet means ending a race?Who the hell came up with this.Jesus,games should really stop judging like that.Anybody can change.You never know what's on their mind. "