A different scenario from that of the trilogy, more successful than ODST. The fall of the planet Reach is told in epic and moving way at once. We live every level of heroic times, followed by disappointment when he realized that the planet continues to fall, and will not be saved by a group of a few Spartans. The emotion is strong, and the levels are well designed: full of possibility, but not too large. The enemies even have the luxury of having become smart !!! (Well, mostly Elites)
Bungie took the opportunity to disrupt weapons available, but, surprisingly, it all remains as balanced as Halo 3.
To be brief: the campaign is just awesome, and the multiplayer is even better than before.
Perhaps the best console FPS.