Could you narrow it down to the one you're most interested in; then I could try to remember more.

The dream with the Half Life + Silent Hill feel was interrupted by a different dream; might have been the rain forest one.

I also remembered a couple more dreams from that time.

There was one in which I was fighting against men with no faces. I don't really remember most of the circumstances of the dream, but I remember it having a very hectic action-filmy kind of feel to it, just guns though, no explosions.

There was one in which the world had a sort of film noir feel to it, and everyone was some kind of animal, mostly foxes if I remember correctly.

And a couple more dreams from before the Atarax dreams.

I had a zombie apocalypse dream a few years ago, but the zombies were more like recast friendly Fallout mutants than the typical depiction of zombies.

One of my only nightmares(many of my dreams might have nightmarish themes, but I don't consider them nightmares because I actually enjoy them greatly) was when I was a little boy, and the portion which I actually remember experiencing was remarkably tiny, just someone repeatedly flipping a light switch. Now that I think about it, I remember having a lot of sleep problems as a child. If I was to try to analyze that dream as I am now, I would probably say that it was about two conflicting states of being, back then it was just nonsense though.

For a very short time, I actually had a dream journal. I have since misplaced it, but maybe if I have some really cool dreams I'll start a new one.