I have created the dmg file for apple silicon you can follow the instructions in the README.md to make it work. You need to download it and then run xattr -cr Nibbler.dmg. If you are using another architecture there are (older release)[https://github.com/Jac-Zac/Nibbler_MacOS/releases/tag/v2.2.1] that should work just fine, I'll make a new release in the future when I get access to a Intel Mac.