I'd argue Halo 2 set the standard for online matchmaking. I don't think younger people understand just how popular xbox live/halo 2 were in that era. Probably how us olders underestimate just how popular stuff like Fortnite is today.
I'd second this. The "advanced AI" was pioneered with Halo 2's Behavior Trees. I'd not give very high props to level design to any of the 3, partly because I so easily remember all the re-used assets and geometry and moving areas, but also because Halo was responsible for what I see as a decline in overall FPS design. From reload mechanics to limited ability to carry weapons, to the level design itself that went from more abstract and branching level design to long corridors with too much linearity. There's more creativity in things like the Metroid Prime series, just because of the need for backtracking and new areas when you get new gear. (Of course the Half-Life series also contributed, though interestingly few FPS games have tried to imitate the physics puzzles.) Later on Gears of War and other cover shooters took that to its own sort of perfection. There's good level design in all these, but it's good in their contexts, not exactly phenomenal or standout especially just looking at the FPS genre. (The multiplayer Halo maps are of course pretty good, but again while it's probably just a difference in taste, I think of them as overall steps down from what was going on in Quake/Unreal and their derivatives.)
I guess I'm mostly just amused by the initial comment suggesting Halo 3 of all games as a super incredible cultural impact game. I just can't see it like that at all -- at the time it was just a capstone to what Halo 1 and 2 set up. And in modern times, Halo is so irrelevant that it's probably going to be on Sony's console.
I don't dispute it had massive hype at the time. I wasn't even an xbox fanboy but I still played it with friends who had the system. I still think its long-term cultural impact is rather minimal, the biggest influences of the series on gaming as a whole came from Halo 1 and 2. And as a sibling comment notes, Call of Duty Modern Warfare released only a few months later and was similarly massive, but unlike Halo, CoD has kept up its appeal and impact over the years, from MW2 and on. (Even newer Halo games ape CoD more than their own roots.) Most gamers haven't played Halo, though hopefully most would recognize its title. In comparison, Minecraft (which came later), has such broader name recognition as well as more people who have actually played it, and continues to have strong and popular cultural impact to this day. It didn't have a flashy launch, though, sure.
Perhaps I'm just missing your argument. Is your argument mostly about the immediate "pop" surrounding the launch, rather than any sort of longer term cultural impact? If so, then sure, I'll grant Halo 3 had one of and perhaps even the largest launch hype of all time from the physical release age. Still it's not like Halo 2 wasn't hugely popular at its launch too, though 3 was probably bigger. And of course the already mentioned Modern Warfare had a big launch, though by MW2 the whole culture of launch hype with midnight releases and camping out and so on was just about dead thanks to digital distribution and such. You had other games later on with crazy marketing too -- how are super bowl ads relevant? Dante's Inferno (2010) is a game I've never played but it also had a super bowl ad I've never seen until now. I'd dare say its impact is far less than Halo's, both at its launch (seems to be a God of War clone) and since.
But if you really are arguing that nothing has had a bigger long-term cultural impact since, the single counterexample of Minecraft is enough to stand against that. Speaking of God of War, there's another franchise that has probably by now out-shined the Halo series for cultural impact. (And maybe worth arguing that it probably contributed to Halo 4's dumb "Press button to beat the Didact" QTE?) I'd even put 2011's Dark Souls higher for birthing a new subgenre term, the "Soulslike", even if it took until Elden Ring for FromSoft themselves to hit the pinnacles of financial success and launch success with the formula. And so many other games.
>MW2 the whole culture of launch hype with midnight releases and camping out and so on was just about dead thanks to digital distribution and such
Not quite. MW2 was the largest video game launch on record by pre-orders, revenue and units sold when it was released. Its release broke nearly all of Halo 3's release records. There was no digital release at launch. It also had a massive advertising campaign. There were large ads in every store with an electronics or games sections to an extent that I haven't seen since.
