What was the supposed trojan found by your antivirus software? Ren'Py games (the framework in which the game was built) sometimes gets erroneously flagged by certain antivirus software.
No..... Since 2018 the rate of virus infections on Mac has increased by 400%, the average threat rate on Mac's is currently 11 per device, Windows currently sits on 5.8. Under half of Mac. A note though this includes malware as well as virus's.
Source; Malwarebytes.
They used to get less, because of lower popularity but due to Mac's coming of age in the last few years there are ample threats now that there is a larger user base.
At a guess, the 32bit version is being flagged because of the way it write protects files that are in use, it is getting flagged as a crypto locker.
You can happily let the anti-virus delete the file if you intend to play the 64bit version.