The Flood, prominent antagonists in the Halo mythos and largely hated by several fans of the series, will not be featured in Halo 4.
“You won’t be fighting Flood in Halo 4,” said Frank O’Connor, the Franchise Development Director at 343 Industries when asked if the squishy, slimy alien race will be featured in Halo’s comeback.
I would like to fight the Flood in the co-op/online modes, but unfortunately, that won’t be happening either. So just the Forerunners then, I guess.
Tons of multiplayer details for Halo 4 were recently released, and seemingly, 343 is overhauling the franchise. And even though fans reacted strongly to the changes and said the franchise is starting to resemble Call of Duty a bit too much, 343 wants to reassure that it still feels like Halo.
Halo 4 is also the first game in the series to boast full HD visuals.