It's mostly general balance adjustments I couldn't do for various technical/time reasons, plus some general "make the Hardcore game harder" adjustments. I've made a couple hundred adjustments, but the most significant are probably:
* Max level with all DLCs installed is 35.
* XP rate is halved.
* Base player health is quartered and level-gained health is reduced by 25%.
* Base Carry Weight from 150 to 50 (related perks/things have also been adjusted).
* Energy Weapon ammo weighs less than its nearest equivalent Guns ammo.
* Energy Weapon durability is in the same ballpark as Guns durability.
* Medium Armor has a small amount of DR proportional to its DT.
* Heavy Armor has even more DR proportional to its DT.
* Power Armor does not require a perk, but if you have the perk, the weight of the armor is essentially negated.
* Karma/Alignment values adjusted all over.
* H2O/FOD/SLP rates doubled, but the first threshold is moved from 200 to 400 (statuses roll over ever 150 after).
* Water and Food drop rates on NPCs is dramatically lower. It is difficult to stay out of Dehydration/Starvation by looting enemies.
* Water/Nuka-Cola/Sunset Sarsaparilla heal much less, but now all restore H2O (alcohols will as well, but at lowered values).
* Default Stimpaks are uncommon. A new variant, Stimpak, Expired is the default. It is not that great.
* The player's Workbench recipe now makes Stimpak, Homemade. It is better than Expired, worse than default Stimpaks, and has the PE penalty from Healing Powder.
* All Stimpaks have weight.
* Pre-Order items have been adjusted to be more well-balanced and not worth that much if you rush to Chet's to trade them in.
* A bunch of fixes I couldn't make during development because of load order conflicts, time, etc. E.g.: Automatic Rifle spread re-adjustment, putting the Police Pistol on the Cowboy List, Bozar on Grunt, Junk Rounds are now actual ammo variants you can make, etc.
* Some other stuff.
It requires a load order manager (must load after all retail .esms) and every single DLC, including GRA and the pre-order packs.
* I played with this mod for about 20 hours. That's the extent of its testing. Really. BEWARE.
* This is not official and it's not a patch. If it disintegrates your game, do a Kareem and skyhook the .esp into your Recycle Bin.
* I didn't add any huge new things because that wasn't really the point of the mod.
* I avoided anything that involved heavy scripting because I am bad at scripting and didn't want to blow everything up.
* Will probably conflict with some of your 10,000 other mods. Sorry.