I have seen all of the episodes of both seasons of this anime
At the end of the 2nd season, half the good guys do not die (referring to the crew of Celestial Being
The only few things i wish were to happen different are this (Beware, season 2 spoilers!------->):
1. Setsuna gets together with Marina..... that is my fav fan pairing.
2. Anew had stayed alive. Seriously.
3.Louise had not ever gone crazy, even for the time she did.
4. Exia had just one more GN Drive (added to the two it has in season 2) >:D Bigger Boom!
5. Nena T. had stayed alive just a few more episodes. (WARNING: These Examples come from the animes i have seen) It always seems to be the redheads who go all B.A. on people (EX: Asuka from Evangelion), get killed dramatically (Asuka got stabbed through the face....and eaten alive in her mech....*shiver*, oh and Sasori from Naruto getting killed by his 'parent' puppets), Get cool scars and rep (Shanks from One Piece), GO nuts and kill everybody
(Garra from Naruto.....oh and Nagato, aka: Pain or Pein), and get caught in the craziest positions, etc.
So not to put down the other characters good characters in anime, but Nena could have had more she could have done if she had stayed for a few more episodes, in my opinion.
These are just my opinions. Overall, this is a great anime