I played them all at launch, owned both systems. Halo was revolutionary in terms that shooters finally played okay on consoles...though Halo 2 had great M.P. Killzone had a great single player, had offline M.P. and had great online. No haters, please.
P.S.N. - Matface. Go forth; touch the Demon inside of me.
Please go into depth, eventually I will go into depth.
What depth are you looking for? The gameplay is clunky and unimaginative. Online was slow and a real bore to play. The story wasn't great other than a few decent action scenes. The series got progressively worse each time with Shadow Fall being one of the worst games ever made.
Killzone 1 had splitscreen bot mode. That was fun. The following two were disappointing. Halo has coop splitscreen. Haven't actually played any after the first game. If the later Halo's had a bot mode with splitscreen as well as coop campaign then that would be a win.
You're the hero Gamefaqs deserves, but not the one it needs right now.
I paid 5 bucks for Killzone 2, it kills me trying to use the dualshock 3 for a game like that, why couldn't crouch be the circle button? Also, Killzone Shadow Fall was pretty boring when I played it on a friend's PS4.