The story right after the temple fight was a what they should have done to end the anime version. It was perfect! I mean, it was Kurono vs. a bunch of short freeza form 3 looking type aliens. No one else, just Kurono. It was a badass fight.
Plus what's cool is he failed the mission and then having the last remaining alien come after him to school outside of the game of gantz. It's also the story of where Kurono first finds what he will realize is true love with a girl he was forced to go out with because of a lost bet with his only 2 friends that very soon end up dying along with pretty much all of his class except that girl he had to ask out because of the bet.
The police also got pwned hardcore too. Also, if you remember that magazine model he was oogling in the anime and manga at the beginning? Well, she becomes a contestant in gantz after the freeza alien story too.
You also get to meet a former gantz player that returns to the game after a while away, he's kind of a dick at first but turns to be a badass later too. Great manga even though the current story is being dragged on wayyyyy too long.