Obtain the APK file (the app itself) and the data/OBB files (the game data) from reputable community sources (often Discord).

To install an APK, you must enable "Install from Unknown Sources" in your Android security settings. This grants the file permission to write data to your device, making it vital that you trust the source completely. How to Safe-Check and Install Android APKs

For a more secure "mobile" experience, some players use PC-on-Android emulators like . By importing a legally owned .exe file of the game, players can run the official version locally on their phones with high frame rates, avoiding the potential bugs found in standalone fan-made APKs. Cuphead - Games Rating Authority