In the event you were trying to flash a ROM for a different model, hopefully you just soft-bricked your phone. Flash it again but be sure to use a ROM that matches your specific model of G4 Play, and that 'should' restore it back into working condition. Don't use a ROM that's for a different phone model, they're not interchangeable.
If however you hard-bricked your phone that could be a real problem. In that case you might want to just take it to a local service shop to have a trained tech person look into it.