Ideas that may fit to UII

Texture of props
There are some details of certent objects like: Guns,Trees and other stuff.
But i thinks is not enough, there should be some tweaks to colors because a f.e Fire axe that have been added to the game change shapes only it’s good but better approach to make it look good would be also a more palets of color added to it like:grass for now on its just green but maybe on top of that triangle would be dark green.

Neck
If you might not notice that “denizen” or player model have neck you might see that its small piece of body and let me show you what it could be done:

Armor neck
Firstly we need a piece or pieces of slot to the armor carrier (maybe some sort of carrier or you could modify one) that allow a armor plate to be put in for neck protection.

Neck-backstab
It will play 2 or 3 second animation (maybe it would be a each individual animation for every each type of melee weapon) from count as a instat kill of course it must be done from back of the neck a (it can be prevented from having carrier that have armor piece from back on neck or just make it hard to hit for the neck backstaber)

As a weak point
1-shot for bolt-action weapons
2-shots for full-automatic weapons
1-shot for semi-automatic weapons
2 or 3-shots for semi handguns
1-shot for revolvers
( in this same exactly way as neck backstabing also can be protected by neck armor)

Objects as a efective weapon
they posses a physic ability and can be thrown or pushed to make significant damage or instant dead (it may depends of weight and velocity of object) for example: you can throw rock at some one and push at someone trash containers with wheels.

"Grabbing" technique
It’s a kinda great technique and cool one, it should work like that:
1.wait for the strike/blow/swing
2.unarmed,armed with gun,armed with one-handed weapon or armed with two-handed weapon try to grab arm or hand of opponent with your non-dominant hand before geting hit.
3.now you can hit,kick or what ever to deal as much of damage you can
4.your opponent can block your attacks while you immobilized him(idk if attacking and blocking will depends on direction which you attack or block if so that f.e if someone trying make upper strike that immobilized him from blocking down cuts) or try free his hand by clicking “bash” button that will hit your hand with his handle/stock/elbow to allow him to get himself freed (it’s not intented to applying QTE its just one click to free yourself also by means “can block your attacks” it can but when you immobilized him he well get debuff effect that disable for 0,3 or 0,2 sec his actions so you should be quick what to do.

Maintenance of guns/melee
Cleaning.Sharping.Reparing aka. CSR system appeals for sharp/piercing melee but cleaning is optional.
CR system appeals for guns.CR system appeals for blunt/heavy C is optional as well.
Maintenance requires special items to get your stuff in good shape like:toothbrush,piece of cloth,whetstone,materials that you can us too repair guns/weapons (guns need individual parts to repair).

Sizes and shapes of armor carrier
Diffrent types that can allow more places be coverd by armor plates for disadvantage of being slow and vice versa.

Buff and Debuff effects
example:
+Well feeded
quick reg and decrease a weight of all items by 12%
*frezzing
slowing decreaseing your health
+adrealine
15% increase speed movement
and some much many.

Masterkey old brother
A one barrel 8 or 4 gauged feeded Masterkey…

Bolases,nets and ropes
those will pin down person that have been catched by those things mostly i would say how those have diffrent benefits in terms of hunting either in combat.
*Bolases
pin down a person/animal/zombie and can immobilize legs or arms+
have small-medium range+
are heavy-
there slow+
takes 5-7sec to take them off
*Nets
pin down a enemy and immobilize whole person/animal/zombie+
have small range-
can be cut by sharp tools or easly take them off than ropes-
are light+
there kinda fast to thrown than bolases+
*ropes
pin down+
are light+
small-medium range+
are easily to take them off or cut them-
are faster than bolases and nets+
can make zombie/animal trap+
if you miss you need to roll up -

Quick ammo taking
it would be good as option for storage that contain ammunition/mags
and you could just easily without searcing it in container.