I made a few notes in red to change the sound and to provide a definite closure to the thought of the poem. I'm lost at the transition I highlighted in blue. Do the kids age and become lost souls? Or are the lost souls a subset of the adult population? Would it be correct to change the "but" line to "But it's also in the city"? I found this to be an entertaining poem with good imagery.
Nothing like the city
Bright lights
Crowded sideways
Skyscrapers
The coffee shops
The restaurants
The kids playing at downtown
You can hear them screaming
You can hear them laughing
Crying, hugging, fighting
But it's all in the city
Where lost souls wonder around
Maybe they try to be found
But they've nowhere to run
Cause the city is big,
and cruel and
Dark.