This is an extension of the original [#021 - Pellet Quest] concept, but set in a post apocalyptic survival setting. Yes, it involves zombies, which are SOOOoooo over done these days, but the game concept isn't really about zombies, so you can replace them with any sort of post apocalyptic enemy, such as wild boars, mutants, demons, cyborg overlords, or whatever. This is a game about survival, and it has three main elements to it.
Like Pellet Quest, the world is a giant semi-open world with certain segments of it locked off. Since this is a post-apocalyptic setting, we'll say that the basic overworld is a city-type zone with themed zones like an amusement park, military base, mall, sewers, forest, and so on locked until the player finds the appropriate key to enter them.
Unlike Pellet Quest, pellets are not your only resource. Though pellets represent a majority of the open space in the game, you'll also find other resources, like bullets, wood boards, scraps of metal, food rations, and stuff like that. These resources are used to buy things instead of the pellets. For instance, you can temporarily board up a zombie spawning door using two wood boards. These resources randomly respawn after a while.
The pellets themselves represent one's hit points / survival. Every time you get hit, you lose a few pellets. To add even greater pressure to the game, you lose pellets very slowly over time, causing you to constantly explore and find new sources of pellets. You can only hold a certain number of pellets at one time, though this number can be increased through equipment (which can also reduce the number of pellets you lose when you get hit). When you are full on pellets, you do not collect additional pellets - so you can come back and collect them at another time.
As you can imagine, this puts a hard cap on one's survivability. No matter how perfectly you play the game, the constant loss of pellets means that eventually, your character will die. There are a few things that will end up making this easier through survivor rescue and safe havens, but an easy mode might be introduced to either stop pellet attrition or to cause the pellets to respawn over time. A hardcore survival mode, of course, will be available for the preferred experience.
The object of the game is to find the 100 survivors placed around the world map and to lead them back to the safe haven (which I'll talk about in the next section). The game is effectively won once the safe haven is fully upgraded and all 100 survivors have been rescued.
Upon seeing a survivor, walk up to them. They will start to trail your character, going where you go. Find a second survivor and he will go to the end of the trail. You could potentially end up with many survivors following your character, like a snake.
Each survivor has a number of times they can be hit by an enemy before they die. These are not hit points like yours. They do not replenish by picking up pellets, no drop slowly over time. You can have the survivors follow you as long as you want, provided you keep them out of danger. After the survivor dies, they disappear from your line. In hardcore mode, they are gone forever. In easy mode, they will respawn back at their original starting point some time later.
Each zone in the game has a set number of survivors to find (let's say 10) that must be brought to a safe haven. Any safe haven will do, but different options will open up depending on which ones they are brought to. For instance, a nurse at one safe haven may allow the creation of a field medic shop. However, if you bring her to the Hospital-based safe haven, along with the two doctors and a second nurse, it might allow you to build a much better healing shop. Or perhaps reuniting a family of survivors from different areas may yield something special as well.
Each survivor you bring back to a safe haven gives you a bonus number of pellets. These pellets are above and beyond your normal limit, so you can super charge your health this way. The bonus grows exponentially based on the number of survivors you bring back simultaneously (up to a max of 10 - you don't want the train of survivors to be so long it goes on for multiple screens, but you should be able to deliver an entire zone's survivors in one go).
A safe haven is sort of like an RPG town. There are no enemies there. You can drop off survivors at one. They can be upgraded with new goods and services. And you need to supply them with resources to survive.
At the most basic level, a safe haven is where you drop off survivors. As soon as you enter, a little cutscene plays where the survivors thank you and become part of the community. In general, any survivor can go to any safe haven, though there might be survivors that will only go to a specific one.
Each safe haven has a food store, which feeds its members. You must continually locate food in the world and keep the store stocked. As it dwindles down, you will be alerted that the safe haven is starting to get hungry. Take too long and the people will start to die off. The maximum number of survivors for each safe haven is directly related to the maximum amount of food that can be store there.
Luckily, you can upgrade the safe haven using the resources you find around the world. For instance, with a few wood boards and a stack of scrap metal, you can upgrade the food stores to hold more food - less trips to restock it, longer before starvation hits, higher population. You can build different stores, which you can buy items from for resources. You can also build farms, which grow food for the community (even spawning food resources for you to bring to other safe havens). The potential things you can build for each safe haven should be unique to that safe haven (the hospital should look different fully upgraded than the police station).
The survivors are resources, themselves. For instance, in order to build a field medic tent, you need a nurse or doctor. To add armed guards to the front gate (they'll shoot nearby zombies) you need survivors who know how to use guns. This should be where some interesting choices happen, as survivors can be used to a different affect in different safe havens. Do you take the nurse to the nearby police station to be a field medic where you can buy medkits, or do you deliver her halfway across the city to the hospital where you can upgrade the medical facilities to completely replenish your pellet hp bar for free?