Halo tells an amazing story with beatifully crafted music for the ambient, specially in Halo 4. Worth playing from the begining, and the Master Chief collection allows you to do exactly that. What at first might seem a repetitive topic, every element in the story turns out to be exciting and rewarding, adding something new every game, and making the player be interested in knowing more. Now I understand the love for one of the most iconic characteres ever, and Cortana... was something special as well. I really like the space they used in the game to explore the reach and development of an AI.

Factions, politics, exploration, space fights, love, revenge. Its got everything

I recommend the previous to hardest difficulty. Gives an extra sensation of achievement without turning the game into a real struggle to survive. Absolutely recommended