If campaign does not have bull–Yoink- like:
-placing invisible barriers outside of the map (it’s already bad enough that they’re inside but outside the map too?!)
-10 second countdown: 15 seconds would be a lot better. Or better yet, just trash the whole thing. Think about Silent Cartographer, Great Journey. It was possible to get out so far while underwater. It’s pretty pointless putting 10 second countdowns in deep underwater places when small pools of water are sufficient to exploit the AI, who can’t fire at enemies underwater…. They were used to keep the player in-game and immersed. Yet there was no immersion (unless you’re anti-Chief)
-inconsistent and non-immersive experience: no development time for anyone but Jorge, inconsistent Carter death, inconsistent Noble Six death (how the hell does a guy who just sucks take so much damage and kills multiple Elites with a freaking AR/pistol without reloading?!), inconsistent Emile death (he’s the only one who doesn’t take off his helmet before his death. He went the way of a stereotypical death. There’s also the motion sensor issue), huge lag when crossing load points, small draw distance, bad AI, Noble Team recharging shields even when they’re taking damage, AI Wraiths able to fire from odd angles, BOBs disappearing without fading into camo, no shield bleedthrough, weapons not changing to the one player brought in cutscenes & weapons not carrying over between levels, lolReachphysics, shotgun trooper killing a sword wielding Ultra, Noble Six having pathetic jump height, health, damage output, etc. compared to troopers and Noble Team members
-inconsistent stealth (the head-stomp assassination is the least likely to alert enemies, throwing a grenade immediately alerts the enemy to your location even before it detonates)
-teleporting invincible inconsistent friendly AI (Noble Team)
-game killing off AI (time based, op dropships, right before a cutscene)
-reluctant AI (AI are stuck in one place, they don’t move or participate in scripting. If the AI drivers on TotS are hijacked, they don’t go anywhere like the AI on The Covenant at Journey’s End. They stay in one spot. And let’s not forget about Hunters. They are now roadblocks)
-inconsistent health (damage sponge enemies, damage sponge friendly AI, poor player health)
-fake difficulty
-overall difficulty emphasis
-removing unnecessary things for the sake of nolstagia, multiplayer, or modernization: H3 resurrection system > all-the-time invincible, CE hog first person passenger seat, CE vehicle health & passenger health display, CE sniper silenced effect, CE/ODST Banshee hover, CE/ODST riding on Scorpion treads, CE sniper night vision
-Firefight waves. These don’t belong in campaign. Campaign AI were supposed to be maxed out in Reach but instead, they were spread all over and most of the time, were in waves or stuck to one place.
And it has many more game modifiers and especially AI modifiers… then there will be a lot of replayability.
Basically, all H4 needs to do is avoid the fails of CE’s successors.