NMS is a great game, with a poor choice of difficulty and balance. This mod is increasing difficulty in different ways.

• Damage

All damage to player is increased, but in reasonable amount. Creatures hit harder, pirates are more dangerous, sentinels damage improved.
Even if this mod is just a change of some numbers, with it battles feel much more dangerous, and in combination with “Sentinels improvements” it gives impressive results.
- low lvl one pirate ship is still not a threat, but higher lvl especially high threat levels — now is impossible to beat without preparations and upgrade ship.

• Biomes

Reduce the number of rich and living planets. More dead planets.
Never feel like its too many planets in systems? I'm always see systems with 6 planets, and all of them full of flora and fauna. Its ridiculous how much life in NMS. This part of mode bring to close it to real space.
Not that close though, I still waiting devs to add gas planets, huge asteroids and other stuff.
Reduce the number of living planets, and increase dead ones. Reduce the life chance probability on planets and systems (race in system chance)
Yellow system
Always have life on planets and dominating race in system
no bizarre planet spawn here anymore
always have 1 or more living planets in system

Green system
Less life and race chance - 40% less than default
20% chance to be abandon type system

Blue system
Less life and race chance - 40% less than default
40% chance to be abandon type system

Red system
Less life and race chance - 70% less than default
95%? Chance to be abandon system (I not change it - its default)

• Sentinels

Improve sentinels AI
Sentinels see and spot you further away, because.. You know - they are literally flying camera.
Drones shoot from a far and non-stop, with greater precision, you don't want mess with these guys anymore.
Drones and Dog have much higher move speed. Laser is improved and shot with greater frequency, but less ray time.
Walker AI also improved, and its almost impossible to beat without personal force field.

• Upgrades

Improve prices and quality of all RNG upgrades. Increase the viability of low lvl upgrades (D-A class) and improve the S grade.
Low level upgrades now cost 90-450 nanites, and S grade is more than 600 nanite for each.

Future plans:
Biom and planet richness - its just too much stuff lying around in planets, why is so many crates everywhere? Broken parts and ancient stuff, all that within 100m from each other. My idea is making them much more rare, but increase the amount of reward. Also reduce the number of gold I-III stuff in planets, make them more expensive and worth to took, except gravino balls - that shit is game ruining junk, but sentinel overhaul should fix it and make balls hunting same danger as breaking alien eggs.
Free Freighter - i honestly don't know why devs make that decision, its so game breaking, that 'feature' should be removed. Freighter must have a great price, it's an endgame stuff. Sadly i don't know how to do that, and only can recommend you ignore the call after freighter under attack event. If you want to play this game and having feel of progression, don't take free freighter, its a trap.pic.

Installation
To install, follow the usual steps.  Place the Pak file in your mods folder at 
steamapps\common\No Man's Sky\GAMEDATA\PCBANKS\MODS 
Be sure to delete or rename the "DISABLEMODS" text file so the game will know to load pak files.

Recommended mods:
 No Glowing plants  https://www.nexusmods.com/nomanssky/users/87374  and No danger marks https://www.nexusmods.com/nomanssky/mods/759  from Lo2k. These tho is vital, and fit perfectly with new difficulty.
Chemistry Overhaul https://www.nexusmods.com/nomanssky/mods/1027  from PetrikM

To install, follow the usual steps.  Place the Pak file in your mods folder at 
steamappscommonNo Man's SkyGAMEDATAPCBANKSMODS 
Be sure to delete or rename the "DISABLEMODS" text file so the game will know to load pak files.

0.7 - end of my own testing stage and  first oficial release