The "Limbo Mac OS X.dmg" refers to two distinct tech experiences: running old Apple operating systems on Android devices using the Limbo PC Emulator , and playing the award-winning indie game 1. Limbo PC Emulator: OS X on Your Smartphone
or Steam. If using a standalone DMG, you drag the game icon into your Applications System Requirements Limbo Mac OS X.dmg
If you want, provide the .dmg’s checksum or a link/source and I will help verify provenance and walk through safe inspection steps. The "Limbo Mac OS X