Critique of The Vision by Omeganaut

I enjoyed the idea of the story you're trying to tell and think its a great place to start, but you have a few things that could use some work.

I loved the way in the first two paragraphs that used (mostly) the present tense: it gave the narrative an immediacy, thrusting the reader directly into the trial of the speaker, but you seem to have trouble staying in one tense. For example, the first two sentences read like this:

An ordinary man, overworked and underpaid, finally vents a scream of frustration. In accordance with all laws of physics, it echoed in much the same way that concrete floats.

You clearly begin in the present tense, in that our ordinary man "vents a scream of frustration" but in the second sentence you describe his scream as having "echoed". Something to keep in mind is that once you use one tense, you should try to keep the remainder of the story in the same tense. So these first sentences should read as the speaker "vented" a scream that "echoed", or he "vents" a scream that "echoes".

This is merely an example of this issue, but its something that you do quite a bit through the story. While I think it would work well either way (though I'm partial to the way it reads in the present tense), you should be mindful of keeping the tense consistent throughout.

Something else to keep in mind is the rule of "Show, Don't Tell". For example, when the speaker hears the voice that sends him on his path, you describe it as being:

"Strong as any announcer and more forceful than a dictator"

While this description certainly gets your point across, it begs the question: how is it more forceful than a dictator? How does the strength and power of the voice make the speaker feel? It must have been something incredibly wondrous and frightening to make a man, even one on the edges of despair, give up everything he had to spread the message he hears. Like I mentioned before, I like where you are, but you should try to flesh your descriptions out more.