I want to give my two cents and suggest small, tangible, but not insignificant improvements to the first level of the mod.

In the Pillar of Autumn, Johnson holds a Sniper rifle when rallying the marines. This is cool, but it was surprising to see this in every difficulty. I’m not sure if everyone who will plays the mod know of the lore behind the character and it sorta sticks out (literally, the stock protrudes out of his arm), especially when he was just another recurring extra throughout the game like most of the other marines (Stacker, Mendoza, etc). If possible, I would suggest having him keep the Assault rifle in difficulties below Legendary. This way, players can still be introduced to the original cutscene and the changed cinematic would subtly allude to the Maw cutscene only viewable on Legendary as well as hinting his background for those in the know.

Another gripe to me would be when meeting a squad of ODSTS pushing against Covenant troops blocking the escape pod latch after exiting the tunnels. This is awesomely done, but then the cutscene plays and only marines are on the seats. Did they stay on the Autumn? Where did these marines come? They were only two injured at the back of the hallway? I can see it’s purpose, but given the helljumpers were already introduced by this point (twice on legendary), I think the vanilla game handled it better when it implied the marines that aided you when making way for the escape pod joined you in the following cinematic. Same verse as the first, keep the marines in all difficulties except on Legendary, where players who are already be accustomed experience something new while reminding new players playing on lower difficulties the camaraderie of the marines.

This isn’t to say that I’m not blown away with the mod (I’m in fact am!), but wished to give suggestions in earnest to help make this mod closer to perfection for everyone to enjoy.

the ODSTS are fire team RAven and they did stay.

Ruby supposedly has said he's returning to this mod at some point. I think these ideas are cool but I think it would go against Bungie's intentions for balance (at the time obviously) to add a sniper enemy to the game, as evidenced by the fact its the only weapon not usable by the flood (that the player could equip). But outside of semantic nonsense, I think Halo CE is the best designed of the series for combat, every projectile is dodge-able, and while yes, the flood fire hitscan bullets, they have horrifically poor accuracy and quickly give up firing in favor of melee combat. Snipers have never felt good to fight in any of the games. Try out cursed halo if you want an idea of how annoying snipers in CE would be. I also understand they're essentially designed to miss the first few shots, but that just makes them more fair, not fun. What if there's more than one? What if you're out of ammo in any weapon that has a solid chance of being able to hit a ranged enemy? CE isn't like the other games where you have a dedicated sharpshooter weapon with nearly limitless mountains of ammo for them. I can't see it having a positive impact without some significant overhauling.