I am very sorry to fans of the project - Halo modding is time consuming and quite punishing when MCC updates break hours of hard work and testing. I will not be updating this mod until 343i release proper mod tools that bypass the update breakage.

It has come to my attention that I have likely not accurately described this mod as potentially more difficult than regular Halo. Of course, that depends on your level of skill, but I have found that most of my play-testers found the difficulty to have increased a little. If that's something you're interested in, welcome aboard!

Overkill
This is my vision of a more "modernized" Halo that holds dear the core principles of the Halo sandbox and amplifies many of the systems that make Halo unique. Most of the changes made for Overkill were centered around a handful of philosophical principles that helped shape the mod into a coherent vision.
Below is a simple summary of a few of the over 2950 changes made to this single map!

Move faster, jump farther, spend more time shooting and dodging than hiding (if you are skilled enough) and pit yourself against a Covenant army that has a renewed sense of purpose and might. Fight on equal footing (no more difficulty-based damage scaling) and learn to leverage the unique strengths of the devastating weaponry of the Halo sandbox in order to achieve victory! Your enemies will not hold back, it is up to you to respond in kind.

Visuals such as special effects and character shaders have been modified to embrace the more vibrant, somewhat cartoon-like quality of the classic trilogy and some Covenant ranks have been redefined to fit within established archetypes. Explosions, sparks, overheating gas and plasma impacts have been modified to appear bigger, last longer and look more visceral.

Shields and Health now have a greater impact on how effective weapons are against a given target. Use plasma weaponry to strip the shielding of exalted Covenant warriors, and wield the comparatively primitive kinetic weapons of the UNSC to punch holes in flesh and shred covenant armour. The raw power of a weapon may no loner be the deciding factor of it's effectiveness in a given situation.

Plasma weapons now sport a couple of new benefits, but take more skill to use than before, owing to their slower projectile speeds. A diligent player must learn to anticipate enemy movements and consider the unique behavior of each weapon's projectiles to utilize the weapon to it's full potential. Jackal Shields can now be detonated by overloading them with plasma fire, dealing damage to surrounding enemies and causing the victim to flee. Plasma weaponry also uniquely tuned to have far less of an impact on Active Camouflage.

Aim-assist has been tuned so that it no longer corrects near-misses, however almost every weapon (including most automatic weapons) have a much greater level of accuracy and can be wielded to absolutely devastating effect in the right hands. Halo's weapons have never been so powerful, but they now require more from the player.

Every single weapon has been tweaked to define unique projectile velocities, ballistic properties and acceleration ranges. These tweaks redefine the ranges at which combat takes place, favoring close to medium range engagements where the holy trinity (gun, grenade, melee) is no longer balanced heavily in favor of protracted shootouts. Threats now emerge in a more dynamic and engaging manner whereby the range of the enemy, their weapon and their rank become more important factors that drive how you chose to interact with them.

Covenant Dropships will no longer tolerate careless players and will aggressively deter assaults on their passengers if they spot you. Keep your eyes on the horizon and find cover unless you are prepared to dance to their tune! Changes to the turret make it a far more formidable weapon, but it is now more susceptible to heavy weapons and sustained fire from conventional weapons.

Covenant forces will engage a far greater distances and fill the void between themselves and their foes with fire. Previously timid enemies will now hold their triggers down and lay suppressive fire on careless players.

Most weapons now sport greater reserve ammo pools, and are dropped by defeated AI with more ammo. Players that resort to scavenging weapons from the battlefield are given more opportunities to experiment with different weapon pairings and a have little more room for error. UNSC power weapons such as the Sniper Rifle and the Rocket Launcher are now able to replenish their ammunition at Ammo Stations; changes to their behavior and how they now fit into the bigger picture mean they are more attuned for regular use.

In Overkill's native gametype, all classes have the same starting weapons - Assault Rifle/Magnum/Frag Grenades - and the Ordnance drops are opportunities to obtain the weapons that most classes typically spawn with in "Normal Firefight". This fundamental change means that UNSC power weapons are rarer and more valuable, especially when taking into account the point made in the paragraph above; they can now utilize Ammo Stations to resupply. This change also comes with a caveat that will likely break the hearts of some players - the Target Designator is no longer in the Ordnance weapon pool, as it mostly invalidates the design philosophy of Overkill, reducing engagement with large numbers of Covenant forces to a single trigger hold.

Sounds
I am using my own completely new weapon sounds in my game, but they have a way to go before I am ready to upload them. Once finished, I will make the sound pack a separate file for independent installation. Please free to bug me about it - it's something I need to wrap up to release.

Installation

• Navigate to your MCC installation directory (for Steam, right-click on MCC in your library list and select Manage, then Browse local files).
• Extract the downloaded archive to a new folder, then take note of the name of the extracted .map file.
• Backup your original .map file (the one with the same name as the .map you downloaded and extracted).
• Copy the extracted .map file into your "Halo The Master Chief Collection\haloreach\maps" directory.
• Copy the extracted .bin file into your "Halo The Master Chief Collection\haloreach\game_variants" directory.
  

If that is too little information, there are plenty of step-by-step mod installation guides floating around YouTube, they will do a better job than I ever will.

Weapons
I like wasting everybody's time, so here is a slightly more detailed look at the changes made to the weapons in Overkill.

Magnum
Modified to fulfill the role of a sidearm, this particular iteration has a 12 round magazine, high initial accuracy and just enough spread to discourage sustained rapid-fire. Limited by it's much closer range and lower projectile velocity, the Magnum is best suited for close to medium range engagements against soft targets. 

Assault Rifle
Re-imagined as the premier UNSC automatic rifle, this variation of the classic Assault Rifle has a large, 40 round magazine, high initial accuracy and a lower maximum spread which now takes a little longer to reset. An increased effective range grants the Assault Rifle far more legitimacy over medium range, regardless of it's projectile velocity. With an increase in the level of firepower, the Assault Rifle is now a destructive force when employed against soft targets, and performs competently against shielded opponents when wielded with accuracy.

DMR
The often-maligned DMR (it's not the Battle Rifle) has been overhauled to behave like a high-powered, anti-personnel rifle; each round now deals considerably more damage which handily offsets a large portion of its penalty versus shields. A slower rate of fire, paired with the total elimination of functional spread (it is still represented visibly to help guide the pace of firing) culminates in a rifle where the skill of the wielder is the defining influence of its potential output. With the implementation of projectile ballistics, the DMR is harder to use over long ranges, but more lethal than ever in the hands of a skilled marksman.

Sniper Rifle
Similar to the changes levied on the DMR, prospective snipers now have projectile ballistics to contend with, making the Sniper Rifle harder to use over long to extreme ranges. A slightly lower rate of fire, combined with an in increase in the level of firepower and the total elimination of functional spread (it is still represented visibly to help guide the pace of firing) magnifies the importance of landing hits and creates a greater risk versus reward dynamic. Finally, the removal of the 5x zoom limits the influence the Sniper Rifle has over close to medium range engagements for users that are not comfortable "no-scoping".

Shotgun
The trusty Shotgun is a lot more reliable now, owing to a large increase in effective range. A tighter spread and an increase in the maximum potential damage per shot gives the shotgun new licence to be used in a greater number of situations. Users will have to adjust to the new weapon ballistics, whereby hitting moving targets offers a new challenge for those that opt to leverage the Shotgun's newfound range. Useful as an opener in crowded situations, the Shotgun's higher potential firepower makes it great at staggering opponents that are caught in the brunt of it's blast.

Grenade Launcher
The Grenade Launcher has been redesigned to behave a lot more consistently; projectiles detonate on impact now, making the weapon far more effective as an offensive tool. To differentiate the Grenade Launcher more from other explosive weapons, projectiles now detonate a lot closer, reinforcing the weapon's role as a close to mid range opener. Direct hits are incentivised over splash damage, dealing significantly more damage with only a couple of direct hits needed to decimate hard targets.

Rocket Launcher
Modified to behave more favorably when used on targets at medium to long ranges, this iteration of the Rocket Launcher fires rockets that have a slower initial speed, but rapidly accelerate to close the distance for long range engagements. This particular variation borrowed most heavily from Halo CE's Rocket Launcher, which is a more deliberate yet devastating weapon than those that would follow it.

Spartan Laser
Modified to make it more usable in the faster sandbox that is Overkill. This form of the Spartan Laser is more or less the same, but it's faster charge time and greater battery capacity make it fit right into the re-energized sandbox. The Spartan Laser also has no effect on Active Camouflage when fired!

Frag Grenade
Tweaked to behave more like a crowd "softener", this variation of the classic Frag does a little bit less damage, but can hit a greater number of foes.

Plasma Grenade
Modified to emphasize its role as an anti-personnel grenade, this Plasma Grenade has a tighter explosion radius, and deals less damage, but is more lethal than before due to the lower health pools of most enemies.

Plasma Pistol
Modified to magnify the difference between the uncharged and charged shots, this Plasma Pistol variation overheats more readily than the standard Reach equivalent, and while its charged shot is slower, it is far more potent - capable of killing weaker opponent in a single, devastating blast. Like all of the plasma weapons, projectile velocities and acceleration ranges have been tweaked to bring the weapon into more of a close to medium range role, with the Plasma Pistol acting as one of the closer-ranged plasma weapons.

Plasma Rifle
Like the other plasma weapons, the Plasma Rifle has been tweaked to specialize at stripping shields, it loses a lot of stopping power against high-health targets. The Plasma Rifle now behaves more like a covenant SMG than it's larger cousin, the Plasma Repeater. Careful timing rewards wielders with a weapon that can discharge plasma at a blistering pace that can also be sustained as long as the weapon has battery.

Plasma Repeater
The Plasma Repeater has received multiple tweaks that solidify it's role as utility plasma weapon. Whilst it shares the overall design shift that limits it's effectiveness versus health, the Plasma Repeater trades some of it's shield stripping power for a slight damage boost to health, making it the ideal plasma weapon for combat with shielded opponents with higher health pools. Manual venting is faster now, and damage per round is higher, but it's projectiles are a little slower to compensate.

Needler
The Needler has received a few key changes that make it far more furious than ever before. A higher rate of fire and increased projectile speed elevates the Needler to a level where it is hard to ignore, but a shorter lock-on range and less effective tracking force users to wield the Needler with more care, in order to achieve super-combines consistently. Super-combines deal less damage now, but have a larger blast radius and are more likely to stagger surrounding characters, opening them up for exploitation.

Needle Rifle
This variation of the Needle Rifle leans more into an assault-weapon role than it's original counterpart. With a blistering new rate of fire the Needle Rifle is ideal for close to medium range engagements, now that it's projectiles spend a little more time travelling than before. Super-combines deal less damage now, just like the Needler, but the Needler Rifle makes up for this by them far more frequent.

Spiker
The pride of the Brutes, this version of the Spiker finds it's new place as an automatic shotgun of sorts. Spitting three spikes per shot, this weapon eats up soft targets with ease. Projectiles have lost most of their range, and travel more slowly too, but the increase in damage potential offsets it's other weaknesses when brought into close range engagements. Finally, the Spiker is one of the few weapons that sport a higher-damage melee attack, further incentivising it's new close-combat role.

Concussion Rifle
Like all other explosive weapons in Overkill, the Concussion Rifle now rewards direct hits over splash damage, making the weapon a little harder to use but also less frustrating to encounter. With a projectile that accelerates as it travels, the Concussion Rifle behaves more reliably at a close to medium range, rather than exclusively up-close. A larger, 8-round drum grants the Concussion Rifle far more versatility as a supporting weapon for regular combat when used in conjunction with other weapon archetypes.

Plasma Launcher
The Plasma Launcher has been modified to behave far more aggressively - a faster charge time, projectile speed and a far greater battery capacity make it much more capable as a anti-personnel weapon. However, a decrease in damage per explosion makes the weapon more survivable for hard targets and vehicles, often requiring multiple hits to incapacitate hard targets and heavy armour.

Fuel Rod Gun
The Fuel Rod Gun is one of the few explosive weapons that benefit from an increased blast radius, but it has a smaller inner damage radius and slower projectiles to contend with. As is customary for Overkill, direct hits deal more damage than indirect hits, but a slightly slower rate of fire make landing direct hits more important than ever.

Focus Rifle
The Focus Rifle sports some of most radical mechanical changes, behaving far more like a Beam Rifle, but still retaining it's unique "focused" damage dealing approach. Now capable of dealing headshots, the Focus Rifle now fires in short bursts that require sustained accuracy to deal enough damage to strip shielding and remove detachable armour. Talented marksmen can drag bursts of fire over multiple targets, dishing out multiple headshots to unarmored opponents.

Gravity Hammer
This variation of the Gravity Hammer has a larger explosion radius, and a greater potential to displace anything unlucky enough to get caught in it's blast. The Gravity Hammer's lunge range and regular melee damage have also been increased, resulting in a weapon that holds it's value well after it runs out of battery.

Energy Sword
The Energy Sword has received a couple of key changes that diversify the manner in which the weapon can be effectively used. The range of lunges has had a dramatic increase, but their damage has been decreased - this separation of the two melee damage types leads to the regular melee retaining the full damage potential of the sword, thereby requiring players to switch up their attacks. Since the Energy Sword only loses battery on kills, the decreased lunge damage allows for the sword to be used as a combat opener against hard targets at no cost to battery, further deepening the potential of the weapon. Finally, the sword blade and effects have been tweaked to more closely mirror the vibrant aesthetic of Halo CE.

Credits
A huge thanks to Bungie for creating a franchise that has given me years of joy, good friendships and a platform to show my artistic vision.
Thanks to 343 Industries for bringing Halo back to PC, your work is getting better every year!
Thanks to the incredibly talented community modders and programmers that create tools like Assembly, Reclaimer and the Model Importing Tool that modders use every day! Thanks Zeddikins, Gravemind, Forerunnner and everyone else that commits to these essential projects!
A special thanks to my amazing testers - AetheroX, Buffalo-Wing Bill, Kaibah and magelord4100, for helping buff some of the sharper edges out of my mod!

If Overkill ends up being something people are interested in, I will endeavor to modify more maps, maybe even the campaign.

Have fun, Spartans.