>>15267523
>small changes
A fucking gazillion. The changelog on the GMDX site is absolutely huge. http://gmdxmod.com
But basically:
The big one is that the AI has been completely overhauled. They'll strafe around corners (instead of moving forwards to their target point and THEN turn towards you), lay down suppressive fire, use melee attacks against you, aggro at more realistic ranges, search areas more thoroughly by opening doors and lighting up an area with flares after glimpsing you, react to unconscious bodies, smoke you out with gas grenades if they catch you in a vent, can react to noise made by you knocking the wall, and a whole bunch of other stuff. Enemies now also wear helmets which can deflect bullets and later enemies will even cloak.
The skill system has been overhauled so Env. Training is much more useful in addition to making armors themselves more useful by making them rechargeable with biocells and only draining energy for stuff like Ballistic Armor and Hazmat Suits when they're deflecting damage. Swimming is replaced with Athletics which ties in with the new Stamina system in addition to granularizing the benefits to swimming speed so it's more useful in that regard. Demolition affects grenade blast radius and how much you can carry per stack. There's also new perks which give you more specialized bonuses for skills, such as letting you mantle stuff with Athletics, letting you hack stuff wirelessly with multitools, increasing the dosh you can steal from ATMs, and so on.
The sound design has been overhauled to give every interaction unique sound effects, reduce duplicates, expand the amount of footstep sounds with surface-dependent footstep sounds, and giving enemies more sound variety so combat doesn't constantly go OOF OOF OOF *clack* *clack* *clack* *AR burst* YAAAAAARGH *AR burst* OOF OOF YAAAARGH OOF OOF.
Augs have been rebalanced to repurpose the function of some augs and introduce new ones entirely. Microfibral Muscle can now power-throw objects (earlier versions would let you power throw corpses and have them burst like a bag of highly pressurized ketchup, you can enable this in the misc. menu). Some augs like Ballistic Protection can be passive where they give you a passive ballistic damage reduction without eating energy, but it and other augs like ADS and Power Recirculator can be Automatic so they only drain energy when they're being used for their purpose, rather than always draining energy when their own. Regeneration has been significantly nerfed, and the Spy Drone now also functions as an EMP missile of sorts. There's also a new combat aug which adds EMP damage to melee attacks to make melee more viable against robots. Your flashlight aug can be upgraded to consume no energy, and your HUD can be upgraded to give you a light meter.
There's new weapon mods for stuff like Damage, Range, and Full-Auto. There's new ammo types, like rubber bullets, sabot rounds and AP rounds. Recoil when untrained is significantly more noticeable, and weapons over the whole have been rebalanced.
There's also new QoL stuff like being able to jump from ladders, being able to move while leaning and leaning up by holding both lean buttons, being able to pick up corpses without having to loot them, being able to activate consumables and other objects in the world instead of only in your inventory, secondary weapons which lets you bind stuff like melee weapons, grenades and throwing knives to one button, variable zooming for sniper rifles with the mousewheel, inventory shortcuts where RMB activates items and MMB drops items
There's a new Hardcore mode where quicksaving is disabled in favor of manual savepoints scattered throughout the map.
I'd also recommend getting RoSoDude's GMDX Addon, which adds stuff like drugs having positive effects but negative withdrawal effects in addition to an addiction system, letting you recharge equipment using repair or medbots, new weapon perks to make each type more distinct, Silent Run also gets a minor speed boost, Shifter-like red dot behavior so it's not always 100% accurate, the base ammo capacity for everything has been halved but upgrading skills increases your max ammo capacity for that weapon in addition to there being a new aug which increases universal ammo capacity.