Ammo shouldn't be a problem, well at least it shouldn't be. My reasoning for that is there should be an emphasis on unconventional weaponry and fighting. Say for instance your character holds themselves into a hardware store, 2x4's could be fashioned with nails as striking weapons, cordless pneumatic nailers could be used as lethal and quiet alternatives to guns. Pallets can be fashioned to overhead racking using rope and dropped unto unsuspecting/inattentive pursuers. Propane tanks can be detonated with a spark and machetes, axes, hammers, mallets and chainsaws all can be used. Honestly there is a plethora of tools at a persons disposal in the real world. I work at Home Depot so if there was a zombie apocalypse I'd go there with a walmart or super market next door. Its perfect for barricading as well with all the wood, nails, screws, shopping carts and backup generators. Corrosives, like drain cleaners put into a power washer would be epic! Or reciprocating saws as a primary melee weapon would be great just keep your charger and spare batteries handy, it would alert more infected because of the sound though. Also kerosene, gas, wd40 or any other flammable fluid couple with an igniter and a place into a power washer, its game over. Just have to have a steady supply of the fluid and an electrical outlet/generator. So many possibilities!
Walmart presents many of the same survival opportunities plus food. They have a sporting goods section and bows make for quiet killers. I truly hope searching for food, medicine/antibiotics, shelter and ammo plays a big part. Would make for a more gripping and harrowing experience. Trading with other survivors and earning the trust and help would be a cool function too. After every skirmish you'd check wounds to see who'd been bitten and have to make a moral choice of whether to kill the infected immediately or when they turn which may occur while you're sleeping, journeying or in battle. Your choices would affect the morale of your group as well. This would give rise to questions like "is the infected already dead once bitten" or "should they be kept alive to aid until they turn"? I think if the game does that and effectively/realistically show how those choices not only bring the group together but also splinter them (because let's face not everyone would agree on what is best in that situation) then the game would definitely surpass Uncharted as a franchise from all dynamics.
I hope sound, shadow and lighting are all used to convey that sense of emergency and survival. Move too fast and enemies will hear you, don't treat your wounds and enemies will smell you. So its imperative to use first aid kits on large wounds that are bleeding profusely. The girl having here ovulation cycle may be too mature for some but I think being used once through the game and finding a convenience store to get tampons would be cool if used correctly and once during the game since there may be a day and night cycle. Shadows and light should be used to evade or trap/trick enemies if the player is low on ammo or would rather misdirect than engage in direct confrontation with the infected, or throwing items or pitching sounds to send the infected else where.
Just some stuff I'd like to see from the game. Bring me aboard ND!!!