Point of this game is harem collection, so as long as you have new girls coming (that's it, new event every 2 weeks, there will not be game over, ever.
Then, every event also means 17 FG (2x8 from maps and 1 from event girl) so every 3 events you will be able to try your luck in fishing somebody from ever-expanding roster of premium girls to expand your harem even more. Or, to do more rolls in lucrative promotions like guaranteed gold ticket one later.

But why collect past full gold / rainbow squad, you might ask? Ha, waifus are rewards on their own. If people can't see that, then this game is clearly not for them