Life is never easy, well for most of us at least.
The only stable staircase is leading absolutely no where.
An open door with a set of stairs that can't be accessed any other way, leading nowhere for anyone coming out of the door. Perhaps giving them a vantage point to look at others failing to make it to the top, themselves in no better a predicament.
The room the broken stairwell extends from could be filled with the height of luxuries, but given where this is at, it's probably just as broken and decrepit as the stairs themselves.

Though it is of my liking to picture such a thing, the scoffer's in that little room, laughing and criticizing all who are trying to make it, oblivious of their own failures, only making it hard for those actually trying.

The usage of a rather bland (not insultingly bland I must state) cardboard like brown, I'd view as symbolizing the very bleak outlook of the whole piece. The fact that everything is angled, boxed in, linear, more vertical than horizontal, emphasized by that of stairs, broken most of them, symbolizes, to me, great struggle.
Climbing (vertical) is much more strenuous than walking (horizontal.) When I ever use angles, I use them to symbolize limitation, restriction, confinement, where as things circular or curved I would use as a means of expressing the very opposite, that of freedom and hope.
The other color being black, which, again in relation to my own understanding of the color could mean anything from a depressive melancholy, to sinister evil.
However I notice you use little shading here, which leads me to believe one major focus of this piece is an utter bleakness surrounding. Knowing there is a long upward climb ahead, also knowing if there is a way out, it will be difficult, long, and continuously bland and bleak.
It would be here I could imagine many people giving up, deciding to live a rather bland uninteresting life, rather than pushing forward. I've been there.
Perhaps the boxed in cardboard colored walls could be thought of a precursor to the bleak homeless old man living in a cardboard box after he just gave up.
HOWEVER, the shadows that are cast show there is indeed a light at the very top of this labyrinth, it's just that unlike the "light at the end of a tunnel" this light is much harder to reach.

As I indulge in my own little imagination about your picture, those pesky folk who live in that little room, relishing those who try to climb this fail, are living in a very dark room.
The darkest aspect of the picture, aside from the constricting dark boarders I only just took note of now.
Putting further emphasis that the only way out of the bleakness is up. As you can begin to see hints of the darkness accumulating at the very bottom!

Okay, now for the four part rating system.

For vision I give you five stars, as you said "There is only one way up, and it is a tricky one." There is also much more to this picture then a simple tricky way up, though that is all that at first appears. You managed to portray something far greater than a mere tricky staircase, as I'll continue to go into throughout this Critique.

Originality I give you 4 1/2, I was going to give 4 but then I remembered the whole manner in how you shaded everything.

(I get a little off the direct meaning of this picture here)

It really is hard to place originality on art, a man can be the first to spit on a piece of paper but wouldn't really be considered original because he was probably just some guy who felt like spitting.
But the artist who spits on the piece of paper would most likely be using it as a form of expression.
Be it a manner of showing his disapproval for the current trend in art, or perhaps as being ironic, mocking others who have done similar things.
Of course there is always the Andy Warhol way, where he would say something like: "Well I had a nasty taste in my mouth, and um, I saw a piece of paper and decided it would be better to spit in the paper than on the floor."
Then he'd go and sell that piece of paper for a quarter of a million dollars. Which is why Andy Warhol is fucking amazing.

But I digress.

The fact that anyone could draw a set of stairs, some aesthetically better than others is a given, the fact that you've drawn these stairs, and in such a manner, shows what I would find as Originality.
You've an idea and this is how you are going to display it visually.
(Granted it could be completely different than my own assumptions on this work.)
A painter could draw a staircase exactly as it looks, and while his aesthetic abilities may surpass, it lacks meaning, aside from whatever subconscious things we could come up with from viewing his photo-realistic staircase.
Therefore yours is far more original and done much more Artistically.

Technique another 4 1/2, a large part due to how bland and lifeless you've made so much of the picture.
You could have easily made this picture detailed out the ass, but you chose not to.
This picture represents a place no one would want to be, though we'll all be in places like this throughout our lives. However, the saying "It is always Darkest just before The Dawn" becomes apparent in this piece, as, when looking from that perspective upward, not toward the light above, but the other stairs, we see the most dark shadows cast. That very nature also implies just how sunny it is up above!

Surely atop this stairway is joy and happiness, though the struggle is presenting itself, and the darkness tries it's best to persuade us otherwise, (as do those bastards who live in that little dark room) the light can shine brighter just by looking at how forcefully cast those few shadows nearing the top are!

For impact, I give this a 5 Star rating, as it obviously has had an impact on me, it is so often I feel this bleak helplessness about my future, but surely, there must be something worth going through this struggle.
Something those who live in that little dark room only wish they could conceive, but for them, the light of their day is trying to break others down.
They would never appreciate seeing the sun had it come down and lit up their whole room!
Of course I've taken some liberties with this part, kind of putting my own relation to this picture into this critique.

Anyhow, great job on this picture. I noticed your signature seems to have illuminated the firmly placed black boarders, perhaps symbolizing that you have actually reached that sun?

Anyhow, great job, glad to Critique this piece, as this would be my first Critique given.

Keep creating,
~Mike