you know honestly i wonder if there's something wrong with me; i finished it yesterday on heroic, and i loved it, barring a few points, i thought it was fantastic; final boss fight was lame, but loved the drive off; second to last level did blow chunks a bit as noted by others, but all in all i just really dug it, and i really get into the story too; i'm an avid science fiction reader and this story is by no means very unique but i still find it compelling, not because of the plot per-se, but just how it is visually and audibly presented, to me it was a compelling fun game; and yeah, it could have been better; needed more diversity of enemies, better AI, more diverse missions, but all in all i just love the halo formula of: throw grenade, run around other side of wall, shoot, pistol-whip, run back, toss a buble shield down while taking a grav lift up, toss another grenade, then plunge your warhammer down upon some unsuspecting brute
i just dig it, and i'm not a little kid, and not without more epic scifi experiences, so sue me....