t.yamade above is giving very bad advice. Do not uninstall your antivirus unless you are immediately replacing it with another antivirus. Windows Defender is an acceptable antivirus if you are on Windows.
Can confirm Bitdefender flags this as a false positive for regular version. No issue with the alt. version without custom icon. Virustotal shows a consensus that the executables are not malicious and I ran them in a win7 VM with hijackthis and procmon just to be sure, doesn't look like the executables are doing anything weird. I was giving my itch.io folder an antivirus exception for a bit, but I think I'll just use the version of the game without the custom icon.