!!! JUST FOUND OUT HOW TO PASS THAT "BUNDLE ERROR" !!!
1. Install the original app from Play Store.
2. Open it, login as usual with your GPG Account.
3. Just skip the intro, then on the "Character Selecting" window don't select/start the game, just wait until all the resources downloaded.
4. After all the downloads finished, close the game.
5. Go to Android —> obb —> change the name of folder "com.aldagames.polygonfantasy" to "com.aldagames.polygonfantasy.xxx" or anything u want.
6. Go to Android —> data —> change the name of folder "com.aldagames.polygonfantasy" to "com.aldagames.polygonfantasy.xxx" or anything u want.
7. Uninstall the original app. Then install the MOD apk.
8. Change the name of folder "com.aldagames.polygonfantasy.xxx" in obb & data to its original name "com.aldagames.polygonfantasy".
DONE, OPEN THE APK AND THE GAME WILL DOWNLOAD THE RESOURCES AGAIN, BUT U ABLE TO GET INTO THE GAME. (You can't login with GPG Account, so just use "guest" login to play the game).