Such as semicolon, dash and closing parenthesis come into play (8)
I believe the answer is:
emoticon
'such as semicolon dash and closing parenthesis' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'come into play' is the wordplay.
'play' is an anagram indicator.
'come'+'into'='comeinto'
'comeinto' anagrammed gives 'EMOTICON'.
Can you help me to learn more?
(Other definitions for emoticon that I've seen before include "smiley, perhaps?" , "Group of characters online" , "Facial expression created by characters in electronic message" , "state of mind symbol" , "Smiley, eg" .)