The following quotes come from the linked thread. I encourage you to read a couple of the quotes. Well thought out from some of the community.
> Major features like Forge & Theatre and significant advancements to those features.
> New gametypes which do something differently along the lines of Invasion or Infinity Slayer. But you shouldn’t make these new things be the main selling points for your game - they need to supplement the core game, not make it into something it’s not.
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> I’d rather see iteration within existing niches rather than attempts at evolving them through innovation. Innovate with brand new features, iterate on existing ones.
> Developers need to be innovative without messing with their core. Developers also need to realize their mistakes, and fix them.
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> The improvement in UI between Halo 3 and Halo: Reach was innovative and cool. The core function was still there, though.
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> Dual wielding was a mistake. It made the sandbox weaker and infringed on the triangle of Halo, so Bungie removed it.
> New weapons / nades
> New maps
> New abilities (thruster, jet pack with limited fuel, etc)
> Variety within the playlists themselves. Force variety on people. Covie slayer, Promethean Slayer as gametypes - it will force people out of their rut and probably reduce boredom.
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> CoD hasnt changed all that much since modern warfare 2 or so and people cant get enough. Don’t change the core experience.
> 1. Keep the core experience the same. Don’t try to be creative here, you wan to make Halo acessible? Don’t mess with the formula everytime a new game comes out.
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> 2. Add in stuff like fuel-limited AAs, Equipment, Invasion, even Infinity Slayer/CTF but keep them in their own niche playlists. If AAs were Invasion-only, would anyone hate on them?
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> 3. Add more and interesting maps, vehicles, gametypes, cool weapons like the GL, maybe new nades. Don’t overdo it, don’t mess with existing weapons (we’ve had 3 completely different versions of the Battle Rifle. Talk about wasted dev time). Can’t really go wrong with more new stuff (Halo 3’s Chopper, Reach’s Revenant, The Focus Rifle and the Plasma Launcher etc.)
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> 4. Don’t force any of these new additions on to the existing fanbase. That’s why Reach and H4 are such a huge letdown, you are FORCED to play with AAs and Killstreaks, and if you don’t want to you have to play Classic Playlists / Customs. Again, if there was a fine balance between vanilla Halo gameplay and playlists with new and exciting stuff, I’d actually like Instant Spawn Infinity Slayer. Why? Because it would add variety to the game, but not completely overshadow and ruin it. Imagine if H4 stayed true to the H1-H2 core gameplay, had ranked and social playlists, and some social playlists had sprint, instant spawn, Armor Abilities and Ordnance drops. Would ANYONE go on a Halo forum and bash the developer? Hell no. 343i however, decides to take everything that people like about Halo, trown in the trash and force their newly created stuff down our throats. Then they wonder about the laughable poupulation of the playlists.
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> CoD does this very well. New gametypes are in their own playlist and stay the -Yoink- out of everything else. That’s something 343i could’ve stolen from CoD. (with the spectator mode)
> Pretty much what aPK said - you keep the core and then add upon it with options, and not make those options the new core. That is what 343 and other developers fail to realize.
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> StarCraft is a perfect example. The game is, at it’s core, VERY competitive and balanced. So first, you’re pleasing that community. But then they added all these options for people to make it whatever they want, literally. You can play League of Legends (what is it, MOBA?) in StarCraft 2 if you want. So now you please EVERYONE. I mean, just look at how Grifball and Infection came to exist. You could play Skiball in Reach for -Yoink-'s sake.
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> While the core game is there, so too are the options to change it.
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> So, if that had been the case, Halo 4 could have been wildly successful. Custom loadouts and ordnance could have adde so much the game but because it was implemented poorly and because it overrode the core of the game, it blew up in everyone’s face.
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> Throwdown is an incredibly fun playlist because its as close to classic as you get. I have no desire to play anything else because of the risk of getting Infinity and having to deal with the -Yoink- it brings.
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> If 343 for to concede this defeat and overhaul Halo 4 to make all standard playlist with Throwdown or “Pro” settings and then cram Infinity into its own thing, people would come back in droves. But they’re too proud and too far gone.
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> There’s no magical fix for this game except to admit defeat and make it Halo again. Otherwise no one will buy their game.