No, the antivirus won't delete or corrupt your games if they're safe to use. Additionally, Avast has a section called Virus Center from where you can manage all the quarantined items. To access it, visit the following URL which leads to the Support page provided by Avast.
Support page: https://www.avast.com/faq.php?article=AVKB21
You will find all the necessary information related to the way the antivirus manages infected or possible infected files.