Okay look, here's the problem. Well, I suppose this is more of an analysis but anyway. You are spot on with the concept that you can convey a message with nothing but game mechanics and rules, that much is extremely true. The thing is though, it shouldn't be a message conveyed through a fucking game translating to text. What I mean by this, is it seems as though you are attempting to sell this off as social alienation. So, the game mechanic is avoiding people. Alright then, so this is self alienation, our mind tells us. But what do our feelings say? Are they saying "Oh god I feel alone and alienated from everyone"? Not to me at all. It's only my mind telling me this by analysing the premise and text, and TRYING to salvage a meaning from it.
Now, a lot of people do this. This turns the biggest most important factor of a game, interactivity, into nothing but something to be analysed. At this point, you may as well have just written it down on a piece of paper for them to look at. But I suppose that would be TOO upfront and not vague enough. I'm all for interpretative art, but there is obviously a message to be conveyed here. Or more appropriately A FEELING. So, instead of using the game mechanics and rules to be interpreted by whatever pretentious critic applauds himself on figuring out slightly vague messages on obscure flash games, you should instead use them to immerse the player and make him FEEL these feelings instead of have them analysed. In this regard, you most certainly did not convey your message. The best way of describing what you would be actually feeling playing this, AT A STRETCH, is that:
1. You objectify people and use them as an obstacle in your way. This is only pushed to the foreground of the player because of...
2. There is an object or substance you really want to obtain a lot. Now, why are the player and character connected in this regard? Well, because what the fuck is this person playing the game for? As some sort of time waster, as something enjoyable, as an experience. Whether intentional or not, this can certainly extend to life itself. So in any case, the ONLY objective for the player is to obtain this item. In essence, this extends to it being the only thing the object in the game wants in life and the only thing that would make him 'happy'. Of course, we don't get that joy, unless the joy comes from progressing to the end to finish this since it's not satisfying at all, but I digress. The point is that the player and the character share somewhat of a connection on that these items are the only thing we could possibly desire, the only appealing thing in the whole experience of this game/their life.
3. When the substance stops increasing your bar of life that diminished from contact by others, most likely symbolic of your desire to live. That bar I'm assuming is a representative of not only the characters desire to live, but also our incentive to play the game. When we collect the object or substance, the bar goes up. This is incentive for both the character and the player to keep on living/playing. So, this being the only incentive for us to really play, when the bar starts diminishing when we collect the substance, we DON'T immediately stop getting/using it. This is the only thing that we cling to, our only incentive to play. Everything else in the world is dark and black, filled with incoherent messes representing people. We don't wish to stay here, the only bright coloured thing in this mess is the object that we have associated with being good and being the object we desire. Even if it's destroying us now, we don't see the point of stopping, there is nothing else here for us,
Now, in this regard, you did a fairly good job of evoking that feelings, and lighting that concept that stenches strongly of substance addiction. With the rest of it however, none of it was strong enough to make the player feel a fucking thing. monotonia was right in this. It IS art to be able to make someone feel a certain way and then go on to analyse those feelings. It's not art to be able to convey a message in game mechanics FOR THE SAKE of conveying a message in game mechanics. If you need someone to literally dissect the fucking game to get a meaning and artistic integrity from it, then you aren't doing it right. It's the same problem with The Marriage. You shouldn't dissect the game to get the feelings, you should be thoughtful and dissect the meaning AND yourself BECAUSE of the feelings you got from it. We don't analyse a game to see if it's fun, but we can however find a game fun and analyse WHY it's fun. Game mechanics shouldn't be a roundabout way to convey a message, it should be an interactive experience to convey feelings to the player.
So fuck The Marriage, fuck Rod Humble, and fuck this game. Make the players really respond and feel some shit before you tell them to go on a treasure hunt on what the fucking game is meant to be.
This may be an incoherent mess, but I'm not fucking proof reading it, it's too long and I'm fucking hungry and shit so suck my dick. Alright, hopefully this 'thing' makes enough sense so you can follow it's train of thought.

I think you're brave for posting something like this. I like the concept, so definitely keep working on it and expand the game if you want.

I would call it an art game, just as I do "the marriage".

I personally felt very immersed into the game. I think it has a very sad message, which I will not rush to call wrong as many else do. Probably because most of the time I do feel this way also. But when I try to be objective, people are probably right about saying that it is a "self alienation", that it is not the fault of others but the player's him/herself. Isn't it miraculous that you try to represent what you live and feel as a game, and the critics are in a way that could be a perspective on the real life problem? I think the power of art games lie here.

As a player it was a meaningful experience for me, so thank you and the other commentators.

It is. Sorry, but having problems with socialization won't be solved by mutual asskissing of "hurt geniuses". A "deep" description doesn't change those are random circles and nothing happens. You can convey deep messages through art. And, through art in form of flash games. But this is not making me feel anything, you didn't made me. And if someone seriously breaks into tears seeing rich social interactions flattened to blue and pink dots (because girls and boys are different lol) and deep special snowflake in between, I call bullshit on this.

I do know how you feel, chap. Nice concept game. Here's a bit of Vonnegut, just to sum ideas up.
o/

Sir, poor sir, brave sir." he read, "You are an experiment by the Creator of the Universe. You are the only creature in the entire Universe who has free will. You are the only one who has to figure out what to do next - and why. Everybody else is a robot, a machine. Some persons seem to like you, and others seem to hate you, and you must wonder why. They are simply liking machines and hating machines. You are pooped and demoralized, " read Dwayne. "Why wouldn't you be? Of course it is exhausting, having to reason all the time in a universe which wasn't meant to be

Kurt Vonnegut, Breakfast of Champions