The multiplayer experience is great. Warzone is a cool idea compared to the older Halo games. Area and things are really fun, with infection, and slayer, a 4v4 50 kill race. Great game.
But.. the campaign is pretty meh. I don't really play it often, but if you enjoy the campaign aspects of other games, you might be disappointed with this one.
I recommend this game, 9/10 stars if I could
