Earlier I had made a thread about whether or not people would like it if 343i added more playable species/variants/classes into custom gameplay. THIS THREAD IS NOT ABOUT WHETHER OR NOT THEY SHOULD. It is about WHAT GAME TYPES YOU COULD PLAY IF THEY WERE. You can get to the previously mentioned thread here if you want to argue for or against that, or to to just cast your vote in the poll. This thread is not just if covenant were playable, but all enemies/allies throughout the series and even new ones in Halo 4 if they add something like forerunners or precursors or new covenant.
Please only post here with ideas about gametypes or to expand on other peoples ideas.
Field Promotions. - Based on your performance in a game you could have in game promotions/demotions. With grunts alone you have Minor, Major, Heavy, Special Operations, and Ultra (aka hero). This could be controlled to handicap veteran players or to reward players for their kills.
Infection with flood. Obviously we could play infection with actual flood and even have AI flood infection forms running around to add to the experience.
Swat with Marines. Say goodbye to killing spartans with a single headshot, let us run around as UNSC Marines in Swat. Maybe ODST, but that could be argued both ways (Please don’t).
VIP with Prophets - Each teams VIP is a prophet and the rest of the team plays as covenant. You could have any combination of protection; say 2 elites, 1 hunter, 1 brute, 1 drone, 1 jackal 1 grunt - whatever you want really. A system that made you respawn as a better species if you were playing well would be welcome.
So there were a few I could think of. Please add your thoughts worth thinking below.