Please follow these Guidelines/Instructions to assist you in resolving your issues: What To Do When McAfee Detects Software As An Infection - How to Submit To McAfee Labs & Appeal
I might add also, it is not uncommon for McAfee and other Anti-Virus Vendors to Detect Games/Downloads/Unpackers as Risky or even sometimes to be considered dangerous. Even on occasions simply the Site in which you downloaded the (EXE) from can make a difference.
http://www.siteadvisor.com/restricted.html?domain=http:%2F%2Fserious-sam-2.en.so ftonic.com%2F&originalURL=679109711&pip=false&premium=false&client_uid=998679836 &client_ver=22.214.171.124&client_type=IEPlugin&suite=true&aff_id=0&locale=en_us&ui=1 &os_ver=126.96.36.199
All the Best,
After almost 3 months of no feedback, I am taking the Liberty of marking this thread as 'Assumed Answered' If that is not the case, please confirm\or start a new thread.