"Clearing Force" is not actually a stand alone short story - it is an excerpt from "Extinction Earth!". This detail is included in the Afterword, but not the Smashwords extended description for the book.
The story is enjoyable to read with some minor quibbles.
I find exclamation points in prose to be annoying! With the possible exception of dialog - for example:
"Harris, monster on your six!"
Which raises quibble number two - if you have a bestiary of monsters ravaging New York, it really helps the reader if you use descriptive names.
When the monsters appear, I envisioned the Harris's team having a conversation like this:
"Movement, looks like two, no three velociraptors in sector 2."
"Some, sci-fi geek you are Dean, velociraptors are like six feet tall and they don't have bright red mohawks"
"Nah, those are the right size, what Speilberg was calling velociraptors were actually Utahraptors."
"Cut the chatter" whispered Harris "Let's focus on what we are here for."
"They don't seem do be doing anything, boss, other than sniffing the air"
"Whoa, Momma 'raptor in sector three."
"Pygmies scattering towards the crowds."
Finally, even if they are aliens they need to be believable - a three headed thing the size of a locomotive that can knock down buildings and moves as fast as the pygmy raptors?