Actually, if you look at the promo pic, the owl is dressed in a mobster's duds. He's your conscience making a failed attempt at humanizing your victims, but the mask ensures he'll never succeed. The player (hero) isn't interested in listening to moral outrage, he wants to get back to the killin'

Doesn't make sense that the biker would be the owl, because he slaughters his fair share of Russians, too.

1. The three masks are 3 parts of his personality speaking to him in his coma dream to reproduce what happened. All missions up to the hospital mission are Richard (i call him that because the rooster mask seems to be his "real personality) reproducing in a coma dream what happened. The store dude is the part of his dream telling him that this is a good place to stay where he feels good so he stays in coma. The bald guy is him realizing that there is something wrong and this is not reality. he pushes him away from the dream.

2.The janitors did hide in the basement of the Russian guys. That way they could make sure, that even if someone finds out where they are they still would make the Russians responsible instead. It would just appear as an internal gang war instead of some nationalists killing Russians. The guys killed by Richard just where the leaders of the Russians

Now about who put Richard in a coma I have 3 theories:
1. Biker Guy: Speaking against that is that Biker Guy smashes Richards head in his timeline completely. The only reason for that would be to make both stories in the same timeline.

2. Rat Guy shot Richard. Rat Guy was another killer hired by 50 blessings to get rid of Richard after he killed Biker Guy because they feared he might get suspicious after that. Rat Guy is the Bald Guy in the police station. Speaking for that theory is that the bald guy in the shops pushing him away from the dream world looks like the guy in the police station.

3. Richard shot himself. Represented in the dream by a forth personality in a rat mask called Richter (German for Judge). After Bald Guy killed his Girlfriend Richard came to the conclusion, that he has no more reason to go on with his life. The sentence what ever you do from now on has no significance means that whatever he does his GF won't come back. It also foreshadows the player that whatever Richard does he won't discover the truth. That the guy pushing him away from his dream is represented by Bald Guy speaks against this because he would never have seen him because Bald Guy has left after killing Richards girl and finding out, that he isn't there. This would also imply bad planing from 50 blessings side.

That the message at the normal ending without the password can be seen as a message to the player is no coincidence. From an in game perspective it is them just avoiding true answers because they know Biker Guy is clueless but many messages in the game have a double meaning. One to the in game story and one to the player.

@Lancastersilk
After reading your interpretation of the 3 masks I have to change my interpretation of them a bit:
Rooster: He seems to be the murderous part. I still think calling him the true personality is kind of right because he is the dominant part of Richard.

Horse: He represents his imagination of his girlfriend talking to him. She cares about his health and well being but is indifferent about the killing because she hates the Russian guys that abused her before he rescued her. It is also the part in Richard that doesn't want him to wake up. To stay in the dream.

Owl: He is RIchards conscious and moral side he wants him to stop his killing.

The line: "You are no guest of mine! and I" told you not to come back here! I see that my opinion of you doesn't matter. If you insist on returning here than I should leave!""
show how his morale is more and more leaving and leaves him completely before he wakes up from the coma.

The line "A picture is starting to take form here...I wonder if its accurate. Some pieces don't quite seem to fit. Or maybe I just don't like the way it looks." from the horse represent Richard remembering that his Girl is dead and that this isn't reality. She leaves after that because his Girl is dead.

Then there is the Roosters line ""Looks like it's only you and me left now... I'm sure you know by now, that this won't end well." After no one is left that cares about him and his morale has completely left him all that is left is blind anger and the lust for murder. He wants revenge. We also have the line "nothing you do from now on has any significance" it shows that Richards killing won't bring his Girl back. It won't give him absolution. It means nothing. This is quite similar to the final monologue from the main character in American Psycho: "there are no more barriers to cross. All I have in common with the uncontrollable and the insane, the vicious and the evil, all the mayhem I have caused and my utter indifference toward it I have now surpassed. My pain is constant and sharp, and I do not hope for a better world for anyone. In fact, I want my pain to be inflicted on others. I want no one to escape. But even after admitting this, there is no catharsis; my punishment continues to elude me, and I gain no deeper knowledge of myself. No new knowledge can be extracted from my telling. This confession has meant nothing. "

I have to agree with most interpretations of the three masks in the dark room but with some nuances. I have to admit I inmediatly thought in Lost Highway when I started playing, so my interpretation is quite influenced by Lynch films (which at the same time, could be close to this freudian line).

I also think the Rooster and the Owl as parts of our character, being the horse the mental representation of his girlfriend, but they're not only the tradicional super-ego/unconscious representation; yes, Rooster is the violence, but the Owl isn't just his moral side, it's an ancentral symbol for wisdom. The Owl is the desire to know, and Jacket has none, he is just carried away for the violence, unlike Helmet who is willing to know the truth about the phone calls. Bear in mind the Rasmus mask is the one which allows us to solve the puzzle and get the 'true' ending. At the end, only Rooster is left because of the death of the girl and his blindness about the truth of what is happening; perhaps it's the result of the mental conditioning the cleaners speak about at the end.
For the Horse, remembering the mask is called Don Juan I think supports my theory of being a representation, it implies romance, and the cover art corroborates it.

And I think the Employee also plays an important role, I would say he's the judge, a filter, and as with Rasmus, I'm not talking about moral but about truth. The Employee tells Jacket the killing of Helmet was fake, it's a mistake in his memories and from here everything falls apart. The delusion is everytime stronger, Jacket rejects the Owl of knowledge until the Employee finally disappears. So I tend to agree with the idea that at some point, everything we are playing is totally fake, most probably Jakcet was killed by Helmet (the encounter with Helmet is atypical, since we previously received a phone call in the floor we were 'cleaning', something never seen previously).

This happens in Chapter 7, and in Ninth we receive visit of SWAT, whom are invulnerable, could they be the first alert that something is going wrong? It happens a level after fighting Helmet and after a level, we receive the most strange phone call (*click* *click* *click-click* *click* *click* *click*...*click* *click* *click**click* *click* *click*...*click*) and we are attacked by Richter. As someone has previously said, it means Judge in german, that sound relevant, At the end, he seems to be jus another masked killer, such as many we ound previoulsy, such as ourselves, but then, why did he attacked us?

I think Richter is a delusion, he's wearing the Rat, which widely represents the most neggative aspects of humanity, and as judge he brings to Jacket what he deserves: pain.
Perhaps he's the last shock of reality, when Jacket wokes up in the hospital, he behaves like a totally different characte, like a totally different game. Without guns, slow... and with grey hair! Our enemies are polices no trying to kill us but wanting to force us to tell the truth, when our character never speaks. Also, when he goes back to the house and put his dresses... he's back again, the same as always, he gets back to the delusion which fulfils killing the cliche mob boss and the absurd ninja girl. So now, the twisted twist, what if when we kill the mob boss on wheel-chair we are killing the real Jacket?

Well, that's all, maybe I said some interesnting things but I'm sure I said many absurdities. Anyways, this game is awesome, as with a Lynch film, everyone can add his two cents to solve the puzzle, even if actually there is none!

This game is pretentious bullshit. Especially if you know Cactus' previous games it's obvious. He just does stuff, then adds details here and there that suggest some brilliant idea behind the whole work and it's enough for lots of people to analyze the thing like it was some friggin' Shakespeare. And the game itself proves this in the "fake" ending where the janitors ask weird questions.

I mean, when I just heard about the game I thought "oh yay, some teenies are making a violent video game and have added some supposedly deep plot to justify extreme pixel violence which they made just for fun". So I started playing and I'm proven right very soon. Oh yeah, it starts with some "oh so mysterious" intro where masked characters talk to the protagonist and who obviously are him. I mean, a nightmarish sequence with masked characters saying stuff like "what do you think who I am?"? Please, there is only ONE possible answer. It's his subconscious talking to him and from now on there's gonna be nightmarish sequences and stuff.

Fast forward: Weird stuff starts happening? I don't know what's real anymore? What? I wake up from a coma and all that happened so far were just memories mixed with obscure symbolism? No shit, didn't see THAT coming. But cool, I need to be stealthy and can't kill anyone which suggests that the game starts being more realistic now, to reflect that the over-the-top violence so far and those super-human bonuses provided by the masks were just an expression of he protagonist's rage caused by the murder of his girlfriend. Awesome! Hey, no, wait, what? The first thing I do is assaulting a police precinct? And the masks I collected previously are still there and still work the same way? Hell no... but yes, nightmare and reality are exactly the same in this game so none of the violence got any deeper meaning or anything.

So it all comes down to this: hero worked as a hitman killing Russian mobsters, got to know a girl on one of the assignments, later the bad guys make the mistake of not just trying to kill him but also kill the girl in the process, he only ends up in a coma, wakes up and avenges her. Credits roll. Stupid.

Oh wait, there's more. I start playing as the biker whom I killed earlier and who obviously was not part of the Russian mob but was also a weird psycho getting phone calls just like the original protagonist - he had to die, however, because unlike the protagonist he questioned the whole shit and wanted to find out who the bosses are. Now I am him, defeat the original "hero" and can find out what's up. Oh yay, I get to talk to the phone guys who obviously represent the developers which is proven by the fact that the same faces can be seen on the company logo and a dialogue that goes like this: "hey, player, look how clever we are, we made you play a non-sensical super violent game with no sense and hope you enjoyed it for what it is". Thank God the biker character represents the kind of player I am. I am enraged by how pretentious and pseudo-intellectual this whole shit was and so is the biker and allows me to slaughter the developers. Awesome feeling.

But yeah, there's also this "secret" ending you get for solving the puzzle. That ending supposedly does add sense to the game's "real" plot by explaining what purpose the contracts really had within the game world, as a bonus some conspiracy bullfuck is thrown in that is supposed to make the player think,deliver the game's TRUE and oh so philosophical message including social commentary which says "don't just follow instructions, question stuff". Well, that message was delivered in a pretentious and non-sensical manner so I still enjoy slaughtering the developers.

I'll admit that I enjoyed the gameplay although I think that the violence was too graphic but heck, that "fake" ending where the phone guys directly address the player represents the game for what it is: non-sensical violence made just for fun with dull symbols and messages shoved up its ass.

This is your opinion and I think the reason why games are often can only be "stories that are plain and simple because they use no way of narrative that forces the player to actually think" or "pretentious bullcrap in which everything is just interpreted by the players". Because that's what every game that goes into a direction like that gets thrown at and the same could be said about most works of fiction in which the recipient has to bring his own interpretation.

Just leaving this here:

http://www.youtube.com/watch?v=AixOBp15KdI

A very different interpretation of the whole game but very interesting and perfectly sensible. It was the impression that I kind of got on my second playthrough where I found there were still many things I couldn't make full sense of and I think it's a possibility that people somewhat ironically overlook, particularly after the default ending.

All chapters before Trauma are retrospection of events that lead to Jacket's present state and happens in his mind. It's something similar to memories of 47 in Hitman Contracts. Did Jacket killed Biker? Of course he did. From Trauma to Final Showdown all happens in reality though highly disturbed by Jacket mind. Epilogue serves it's purpose as "what if" Biker succeeded on his quest to solve mystery behind these phone calls. In that alternate route of events, Biker survived and killed Jacket, also found these crazy Janitors agenda.

Btw, in Trauma, he don't have grey hairs, these are bandages and shadow over hair.