A comma should be used to separate the direct address 'chico' from the rest of the sentence.
This period creates a sentence fragment; the following clause is dependent and should be joined to the preceding sentence with a comma.
A comma is required after 'EYES' to properly punctuate the direct address 'chico' in this quote.
The correct idiomatic expression is 'change for the worse.' 'Worst' is the superlative form and is grammatically incorrect in this context.
