Minor Spoilers:

I'm pretty much stuck on the first boss and I'm quite pissed about it. I feel they went a bit too far with the difficulty on Hardcore for this game to be honest. Every zombie literally takes 5 to 8 headshots, with a critical hit being rare as fuck. You can shoot the legs to make them slower, but why can I not smash their heads while they're on the ground like in the originals? The knife comes in handy, but sometimes you don't have enough ammo, nor wanting to waste ammo to get the dam thing back.

Back to the Birkin fight... I played the original games so many times, and the hardcore experience was challenging, but doable. Here, I walked into this fight with 40 handgun ammo, all the upgrades, along with 2 flash grenades, 2 hand grenades, and 8 shotgun shells, and he still does not go down. Hitting the eye on his arm numerous times and I legit run out of ammo and cannot kill him. They need to send out a patch or something because that is friggin' ludicrous; especially on the first fucking boss.