To be honest I enjoyed Halo Wars, Halo ODST and Halo Reach. Halo Reach for me had a sad and very compelling message; that noble teams story was but one that made up the broad universe that still has many exciting experiences for us gamers. That being said, I have been very intrigued with the thought of Halo Headhunters. It would be a game that requires players to value their resources and use them when only necessary as you are far into enemy territory, operations conducted had no support from the UNSC, and no contact for several months. Relying on each other, a pair of spartans had to work together, plan and strategise, to sabotage key locations and eliminate key targets in the Covenant. The campaign would take a huge turn to deliver and establish a message of self sacrifice which was very common for spartans.
I would be very intrigued to see ANY side project produced, as it deviates from the master chief and provides insight and perspective to different issues and struggles experienced by characters that we, as gamers, can fall in love with. Given that it is integrated very well into the Halo timeline, has a good story that makes me feel DEM feels as I did so during Halo Reach and especially Halo 4.
I would like to see others thoughts 