Asking for some extra critique

[DarkPulse]

I have posted my first story, a first chapter of what I hope to be a long series, and it's exceeded my expectations by miles. I got alot of positive review, and that's awesome, but I also like to hear more critical/less sugar-coated reviews that point out trouble spots or things that could be improved. Negative review helps me build up the positive so-to-speak, but it has been quite absent. So if anyone can help me improve upon my writing by offering a critical review, I'd be very appreciative.

The story is 'Going feet first', a sci-fi/fantasy story about a soldier who was initially in Vietnam but got dropped in a magical place with elves, magic, and all kinds of creatures and dangers.

http://www.literotica.com/s/going-feet-first