I allow installations from unknown sources and have Google play protect disabled. Also I haven't renamed the file or executed it from the ad card.
I'm really at a loss in this case. Do you have antivirus installed on the phone, or anything that could interfere with installation? It could be that your device is incompatible. I've built a arm64 apk for another user with install problems, maybe you could give this version a try: https://mega.nz/#!8PAxhYpJ!7RDJaLiLEA5592t_PUBplFp2BG126dn2AG3ejGkG4fY
If downloading via itch.io is a problem you can always find the links on my personal website: https://perverteer.com/downloads