Not gonna do my turn yet, but I wanted to make a few suggestions for the game.
One, I think that every weapon except sniper rifles and bolt action rifles should have a maximum range at some point. Maybe large enough that it usually won't come up, but it'd make more sense if my SMG couldn't go 30 squares.
Two, bolt action rifles and sniper rifles should probably have a 'sweet spot' where they're most accurate. Maybe 15/10/5/10/15, for 1-2/3-5/6-10/11-14/15+? It'd mean we wouldn't have survivors spreading out so that the guys thirty squares back can be safe while he snipes the Witch. It'd also give a purpose to the Careful Aim thing, beyond 'you will hit with your next shot period'.
Three, the way temporary health is handled makes it seem like the only point is to be able to keep moving if you're hurt. Which might be a decent idea, but it'd be nice if damage taken was split between temporary and permanent health. That way, there's at least some purpose other than that.
Four, multiple ammo types for shotguns, with different effects. Slug and shot, mostly. You can guess what they'd do.
Five, chunky salsa/because it's cool mechanics. Like, if a Jock started riding someone, if that person made a roll, they could point their weapon above their heads, and well...chunky salsa.
Six, weapon customization. You could find an adjusted laser sight that gives a bonus for the weapon it's attached to, and once a weapon is customized, it doesn't disappear once it's ammo is gone. However, customizations can never be changed(you can take them off/replace them, maybe, but they can't be reused), and you only get two on any single weapon, and of course, you can't have two that wouldn't make sense together(Reflex sight(bonsu to reaction shots?) and a telescopic scope csn't be n the same gun, for example) Some might only work for certain weapons; a laser sight isn't going to work for a bolt action rifle or shotgun, after all. Scopes might be attached to assault rifles and give them the Scope and Careful Aim mechanics, though probably weaker(+2 squares, and probably just increase the range, or give a +5, but not in full auto mode). Secondary weapons cannot get customizations(though you might find precustomized secondary weapons, but that has it's own stuff; do yu want the laser sight pistol, or dual pistols?)
Seven, a Noise thing to be added to some guns. Or most. A noise factor, which depends on the caliber and muzzle velocity(aka damage) of the round. For example, assault rifles actually use smaller caliber bullets than most pistols, but fire more of them, and faster, so the noise would be higher. Shotguns have a huge caliber, so them and grenade launchers would probably have the lowest, while weapon with a Silencer(which decreases damage and range slightly, but decreases noise even more) or a flamethrower would have the least. Okay, maybe not the flamethrower, since that makes a different kind of 'noise', but still. Flash suppressors would help reduce the noise slightly, but wouldn't affect damage. What noise would do, is affect the radius that the infected can notice you from, and give them a bonus to noticing you. Double it if they're the ones being hit(this also means we don't have hordes of infected just standing around while we blast a path with shotguns). That last probably only matters to special infected, of course, since common die to almost anything.