Yeh, I have a bunch of ideas, but I don't think you'll want to use them (because I basically jot down the first thing that comes to mind):
Infection (bite) meter
Stealth so you can get pasts Zs.
Candles. Cause I liek candles. I have a red one burning now.
Tinned food With a tin opener
Knifes, Machetes, Axes, Crowbars
Pistols, SMGs, Sniper Rifles, SAWs, Rifles, Flame Throwers, Rocket Launchers, Uzis, Acid bombs, Grenades (smoke, fire etc.)
Silencers, Scopes, Bipod, Red dots, Hi cap mags
Stuff like that .