Its harem done right. Lots of girls with big breasts, lot of different character developments. All the girls have their own personalities that really differ, its not like the author went on a massive copy-paste just to include more girls.
The story is decent. They nailed it with the gods and goddesses and with the greek mythology names. There are plot twists here and there, but I wouldn't consider them crazy good, just decent.
I don't like the "Campione" title. Champion sounds much better to me. Or hero. Don't really know why the sudden interest in Italian. But its not my anime so who am I to bitch about it? That's right! I am a random guy on the internet, I have total right to bitch about it. Anyways I don't like the name.
Its a decent harem. Way better than the vomit inducing random non-sense out there. It has way more combat, ecchi-ness and harem to give my thumbs up. The male lead is okay, not superbly cool.
I recommend it.