|While there doesn't appear to be any glaring errors in spelling or oversights in punctuation, there are some odd word choices to point out for consideration.
"You have the con," did you mean "com"?
Calling a character, "Commander," seemed odd at first, but this was minor and adjusted to quickly.
"Adroit in negotiations," is a fair enough term, although there may be a more accurate word than adroit, "an adroit negotiator," may be more accurate.
"Although single-minded," is hyphenated in my old dictionary, but I admit having trouble keeping up with the times.
The sentry: It was tough to get this at first, but it was easier with a second look. Words connected to the sentry: his, think, felt, believed, satisfied, thought, emotion.... All those italics took some getting used to, but that may just be because of how they look on my monitor.
third dimensional, or three-dimensional "beings"? Either should be hyphenated.
"But it was also in third dimension where Commander was restricted." I think I have the idea of this, but it may need to be clearer. Is Commander restricted to the third-dimension, or does being there limit him.
Now that I figured it out, I was amused and diappointed, because I was looking forward to the beginning of a great space adventure. I didn't have a clue until "nose" and the names of the streets: I first thought of recommending authors not to use their street names in sci-fi! Instead of dropping the ball, you knew you were headed in a different direction all along, so the joke is on the reader. I still read it three times.
There is a very clever writer at work here!