So Halo 5 includes 12v12 Warzone multiplayer with AI enemies; biggest Halo campaign yet, played through two perspectives; enhanced Halo multiplayer that adds to the core gameplay; 20 multiplayer maps on launch and 15 maps free post launch; and dedicated servers with 1080p resolution at 60 fps.
TL;DR In short this is a Halo built for both new and old halo fans. It's hard to argue against this content and even harder with this price.