Playthroughs by Hokiebird428:
Part 1: [Cairo Station, Outskirts, Metropolis] https://www.youtube.com/watch?v=BIqz5...
Part 2: [The Arbiter, Oracle] https://www.youtube.com/watch?v=ujw5Y...
Part 3: [Delta Halo, Regret] https://www.youtube.com/watch?v=n2DUb...
Part 4: [Sacred Icon, Quarantine Zone] https://www.youtube.com/watch?v=U-7d8...
Part 5: [Gravemind, High Charity] https://www.youtube.com/watch?v=4tSvZ...
Part 6: [Uprising, The Great Journey] https://www.youtube.com/watch?v=PKNmB...

Change list:
(last updated: 2020-1-2)

Most Important:
Reduced enemy damage multiplier and rate of fire
Increased your melee attack damage
Increased grenade damage and enabled chain-react grenade explosions
Increased Plasma Grenade timer, made it easier to hear, and added EMP
Increased time for Jackals to aim and fire Beam Rifle (and 1SK only on solid hit)
Decreased Flood Combat Form health
Decreased Brute health

Others:
Increased maximum AI firing distance for most weapons
Increased chance enemies drop grenades
Restored original reticles for sniper and beam rifle
Made Drones headshotable
Fixed heretic (w/carbine) and Flood (w/energy sword) melee attacks
Provided more variety of weapons used by heretics
Made it easier to assassinate enemies without alerting others
Adjusted Gravemind prison spawns and fixed dead enemies coming down lift
Removed grenades from ally Spec Ops Elites (and changed armor to black)
Fixed Carbine rate of fire, and made it start with full ammo (but reduced tracking)
Increased delay between Needler fire bursts for AI
Increased Plasma Pistol damage (but increase is less when used by AI) and its overcharge projectile speed (but reduced its tracking)
Decreased Plasma Pistol heat generated and delay between shots
Increased Plasma Turret rate of fire
Increased Plasma Cannon damage and projectile speed
Increased Plasma Rifle projectile speed and accuracy (but reduced tracking)
Increased Banshee plasma bolt projectile speed (but reduced its tracking)
Increased Banshee bomb damage radius
Made all gray Sentinels have shields (but weaker shields)
Made all Elite Flood Combat Forms have shields (but weaker shields)
Increased Flood Carrier Form speed, explosion damage, and number of infection forms
Increased number of enemies in a few places
Reduced Heretic leader hologram damage
Fixed missing leaves on trees
Increased strength of Master Chief's flashlight
Increased your movement speed
Adjusted dual wielding damage penalty and accuracy for some weapons
Increased SMG accuracy
Increased Magnum accuracy/damage, and it starts with full ammo
Increased Shotgun accuracy (but reduced its damage for AI)
Reduced Fuel Rod Gun initial ammo, rate of fire, and damage
Decreased Phantom Turret Health
Increased Scorpion Tank speed and blast damage
Decreased Wraith mortar firing rate, and enabled its auto mini-turret
Decreased Elite Ultra shield (and increased recharge time)
Replaced many Jackal snipers in sunken chamber on Regret with Elite Honor Guards and fuel rod Grunts
All of Prophet of Regret's Elite Honor Guards have Energy Swords, and his Grunts are Ultras
Made shotgun start on Regret
Made Master Chief start Gravemind with shields intact
Increased chance marines drop grenades (but reduced chance thrown) on Cairo Station
Increased chance marines evade grenades
Made the randomly arriving Jackal snipers on Outskirts spawn at a single location
Increased time for Flood Combat Form to fire Rocket Launcher
Increased Shadow speed
Added Hunters at end of Outskirts
Gave Elite Zealot same health/shield values as Elite Ultra
Increased Hunter health, reduced stun time, and adjusted melee hit box
Removed the banshees behind you on Metropolis
Removed the extra Jackal Sniper waves on Metropolis
Added extra ally with both Warthog and Scorpion on Delta Halo
Added a Brute ally on Sacred Icon
Reduced Brute plasma grenade use and throwing distance
Increased shields of pistons and absorbers on Sacred Icon
Adjusted Flood spawns and Sentinel emitters to fix pacing on Sacred Icon
Replaced all Covenant projectile weapons during gondola ride
Swapped order of Uprising and High Charity levels
Disabled Active Camo on Flood Combat Forms
Limit jackal snipers on High Charity to non-dark areas
Updated Elite ally ranks, several encounters, and vehicle placements on Uprising
Made Brutes on Ghosts carry Brute Plasma Rifles (instead of regular Plasma Rifles)
Fixed the flipped-over Wraith on The Great Journey
Improved Johnson's position and rate of firing at Tartarus
Increased time for Tartarus' shield to recharge