Hard to say since all we know is what you wrote above - we don't know what _is_ in your app or what it does (any reference to a banned tool or service, any ad blocking capabilities, or...?).
It's a long shot, but you could try asking Google (though to do tend towards intransigence to be honest). Or if you were to register you could ask in our Application Development forum, where you are most likely to find people with first hand experience of Google's policies.