Hey Adrianks! I used to play the og games back in the day but to this day it's still fun but maybe you should add cheat commands? I mean it's fun without them but for me it's hard and maybe an shop like the older games that you get coins for killing zombies i know you are busy but i will wait gladly :D
If you know how to use cheat engine then you can hack any game. Dont judge me but i also use cheat engine sometimes,
With cheat engine you can select
-How much health you want.
-How much ammo you want.
-How much bullets you want in a single magazine.
and much more.
If you want to learn how to use cheat engine its very simple just watch a youtube video using cheat engine in any game and apply it to your game. It should work.