I think the game is quite a lot harder than it used to be. Shocker brutes are a real threat.
I think something that would make the game potentially harder is increasing the essentialness of each stat. Right now I’m using a “glass cannon” build of 20 INT 14 STR 4 DEX 4 PER because I just smash enemies in the head with the biggest weapon I can find (sledgehammer, two handed sword) while methed out and don’t really need Dexerity or Perception to fight. My high int allows me to power level quickly with books and build whatever I need to defeat tougher enemies, like grenades or flamethrowers.
I think inserting penalities for critically low dexterity might be good, like slashing yourself with your own sword. Low perception might be penalized by not being able to tell what kind of zombie your facing until they’re up close. For example 4 perception means you wouldn’t see it was a shocker zombie until it was firing arcs of electricity at you.
I would also recommend nerfing the damage bonus you get with with high melee skills. Rather than just linearly increasing damage, high melee skills should unlock new techniques. For example, fighting a zombie a level 1 sword, you do ten damage and do no techniques. Fighting at level 10, you do 15 damage but occassionally gouge out the zombies eyes, chop off their arms, behead them, impale them when they lunge at you. It keeps it interesting.
I mean, if you think about it, fighting with a baseball bat doesn’t really involve tremendous skill. An unskilled man hits someone in the head, that person is screwed. Yeah, a ninja might strike them RIGHT in the temple, which would of course instantly kill them, but the difference between 1 and 10 skill is sort of marginal, ultimately you’re hitting them in the head with wood, there’s not a whole lot of room for nuance. In contrast, a highly skilled man could use the bat to sweep the legs, shove the handle in the zombie’s mouth when they try to bite and push them back, rap them quickly in the forehead with the tip in a stabbing motion, stunning them. Rap the knuckles, disarming the opponent.
Basically, I think high melee skills should give you more options for dealing with a fight, but not necessarily make the fight (a lot) more easy.
edit:
I also think zombies of all types should be given MANY more special abilities. For example, why can’t zombies disarm you? Why can’t they tackle you and blow you over the way jabberwocks do? Why don’t bites to the head cause stunning? Why are grabbers the only ones that can grab? Why don’t all wounds cause bleeding? Why don’t boomer explosions cause knockback damage? All kinds of little things that can be done that make combat more harrowing.