Harsh Criticism Wanted!

[BlakAdder]

This is introduction to a longer piece I've started. Tell me everything you think about it and don't be afraid to hurt my feelings.

Spoiler

Will slowed his sprint to a slow jog and caught his breath. He had outrun them for now. Now he had to think about what to do next. Would there be more down the street? He thought it best to just find shelter for now.
He sniffed his shirt. He needed to wash. He hadn’t been able to clean off for about a month or so. Of course, that had become the status quo in Hollowshaft, given the circumstances.
He took his backpack off his shoulders. It was a big blue hiking backpack that he relied on ever since the outbreak. He carried everything he needed in it, due to the fact that he didn’t have a home. It was heavy, but that just helped him build up his leg muscles. He dug down into the pack and pulled out a large pentagonal wrench he had taken from a fire station around the time the outbreak started. He took off his shirt and tossed it on the backpack, which he leaned against the wall of a building. He then used the wrench to open the side of a nearby fire hydrant. He let the water spray over him. It felt good to rinse off in cold water on such a hot day.
After he was finished, he fastened the hydrant back and put his shirt and backpack back on. He started down the road again when the stench suddenly overwhelmed him. He recognized the stench all too well. He panicked. He had no idea what to do now.
He looked around for somewhere to hide. He saw an alley behind the hydrant he had just used. He seized the opportunity and dashed towards it. He took off his pack to avoid making noise, and hid behind a dumpster. He just hoped he wouldn’t be seen.
As he sat there, the stench got stronger. He dared to peek over the dumpster. Just barely, so he could just see. One of them appeared in the road outside the alley.
As it passed into Will’s view, it suddenly stopped and looked ahead. It made a flailing gesture down the road. It made a strange groaning noise. “Grr. Grr!â€

 

[RavenTDA]

Sentence length variation. You first paragraphi is all the same lengths. You also start off with He, He, He, He as most of your setences. That alone will make it flow better. Never tell the reader anything and rather show them. Like how you say his backpack was blue. Figure out another way to say it or skip it. Passive sentences like that are just fillers and drag writing down. Pronouns are good too. Use them more if you can it is easier to read and especially good if you have the urge to use an attention grabbing word too many times. Once you use a word try not to use it again for at least a page unless you are repeating it on purpose. Because once said twice it will really snag the readers attention or hinder them on reading it easier. Verb choices... "it made" is so bland. Use stronger verbs. His internal dialogue of "please don't let them see me" was already stated by the narator. Choose one. That's all for now. If I had more time I'd just end up painting the whole thing red. So yeah try that for now.

 

[Samboy]

You are definitely not using enough emotive words. Not enough dramatic pausing eg: He had to stop. Instead of: he had to stop as he could not go any more. Small things like that.