No new games, catching up with the world, and filling it with the name of SpazDragon, the dragon with a spas-12.
Things would have probably been more in-depth(I'm not saying Bungie is terrible at it) if it styled in an RPG, similar to Bioware's and Bethesda's games(Take either KotoR or ES: Morrowind for example). Maybe even like Valve's games, which however simple, still shows a lot of complexity(Portal and half-life).
Overall, some gameplay standard could have been achieved by Bungie if they could have put it by an ever-so-slightly different approach. I thought making stories like Onyx and Contact Harvest shed light on other places in the Halo Universe that occurs simultaneously to the games.
Now who's ready for a fight between Hunters and Hunters?