This is Halo

You should play Halo

But in all seriousness, even just for the story you should buy this game. Halo 1-3 is an incredible trilogy that is one of the icons of gaming featuring one of the most iconic protagonists in gaming. Halo 3: ODST grabbed the universe and the greater story of it and told something smaller, but important. It introduced you to a whole new cast of folks who were just human and showed you the grit of the marines around you even as in the other games you are an unstoppable killing machine. And Reach... Reach my beloved. Halo: Reach is likely my favorite game of all time. It really was Bungie's love letter to the series. You're instantly attached to this secondary group of Spartans and put into a situation that you, the player, knows is doomed... even if the characters don't understand that yet. Even now after I've played through Reach's campaign probably a dozen times when I finish it I just sit back and marvel.

Bungie during their time with Halo put on a masterclass for tone, worldbuilding, gripping story with Michael Salvatori and Marty O'Donnell backing everything up with incredible soundtrack after incredible soundtrack.

And then... Halo 4's just kind of there. I didn't hate Halo 4. I played a lot of it back on the Xbox. In many ways it doesn't have the same magic. But every once in a while you get a glimpse at something. The 343 era of Halo is most certainly second class but it's worth playing at least once to keep up. There is still a future for Halo, and it remains to be seen if they can recapture the old magic but if there's a chance of even a little bit of it poking through... I'll be there.

a bit off topic - but should you buy and play this game? Yes, I think you should.