It's one of the hallmarks of the Halo series that it takes what the fans want and then profoundly ignores it.Sniper Team 4 said:Wait...did I read that right? There are fifteen missions in the campaign, and twelve of those missions you are playing as Locke and his team? Which means that I play as Linda--er, I mean Master Chief--for only three missions? Not going to lie, that's more than a little disappointing..
Halo 2, skips over the first battle of Earth in two missions and punts you back to another Halo.
Halo 3, skips over the fight in the Dreadnought and the second battle of Earth, briefly focuses on the defense of Earth only to punt you off to a Forerunner installation containing yet another Halo. Also skips over the adventures of Arbiter and Half Jaw (UNACCEPTABLE!).
Halo: ODST, actually that one's pretty cool.
Halo: Reach, skips over Operation: RED FLAG and the Spartan II's ill fated defense of Reach for some randoms you never heard of before and never see again.
Halo 4, skips over the tale of Chief and Cortana trying to get home and instead shoves in a Forerunner bad guy and yet another doomsday plot.
Halo 5, skips over Master Chief/Blue Team's search for Cortana, 117's increasingly unhinged state and the chain of events that led to Cortana suddenly being both alive and the bad guy. Instead puts in some new guy's shoes for a round the houses tour of places and people we have no reason to care about. Brings the Arbiter back but no Shipmaster Half Jaw (ALSO UNACCEPTABLE!).
On a side note Halo's various trailers frequently show or tease things that bare no relation to the game too. So Halo 5 carries on the tradition of demonstrating why Halo fans are the most forgiving in the world!