Here is the flow of the game so far.
First day: Moderate amount of zombies. Nothing particulary hard, there are no advanced zombies, though you have no equipment or skills so you do a lot of running.
Day 2-4: Civilians get a hold of the situation and there arent that many zombies. They are like free days basically. Though, a lack of food is quite evident and you can die of starvation if your not careful
Day 5-8: Zombie waves are getting larger, and you see fewer and fewer civies. The army might have come by now, and you have seen a few advanced zombies.
Day 9-14: Things are getting tough. Civies are getting rare, and you are seeing a lot more zombies. Food isnt too scarce, depending on how many air drops you get. Staying at a safehouse for more than one day asks for trouble. You see advanced zombies every once in a while, the bulk is still regular horde.
Day 14-21: This is where you're likely to die if you got this far. Zombie waves get bigger and bigger, with sleeping becoming a problem since zombies follow your scent and attack you(when your sleeping you have no protection or defence). Depending on your luck, food may also be scarce. Any weapon ammo besides pistols is almost nonexistant and its recommened you use pistols(I think police officers bring ammo with them when they spawn, but they die quickly, so they dont use the ammo). Lots of advanced zombies, and you have problably seen a few HFS. The special items in the CHAR offices may be of good use right now. Zombies are also almost endless. They come in a steady stream, it appears they can hear bullets or something. So holding onto your favorate safehouse is likely out of the picture. Pills are extremely important for those certain moments, if your are trying to outrun an HFS or cant find a place to sleep(I think half of my sleep poitns were just blue pills).You count how long you live by the hour, not the day.
Day 22 -?: I havent ventured into this area much. Going into differant districts is actually rather dangerous, since you dont know where food/health drops are and the fact that you have been keeping the zombie population at a moderate level isnt applied. HFS zombie in every group, your probably running a lot. "The Other guys" also pop in a lot, if that is a godsend or a horror depends on your situation. Food may also become sparce(airdrops seem to be far and few inbetween), so you may have to start eating rotten food. Light eater/awake helps a lot. Basically now your just trying to survive between zombie mobs, every sleep is likely to be interupted, so get those medkits out, and have
funI probably forgot things, but thats kind of how the flow feels for me. The days arent exact, I just pulled random numbers from my head.
Also, a suggestion if the developer still reads this...
Give the trackers that find zombies a range for the entire minimap, or give them a higher charge. They are kind of useless as of now because they take up a slot in your backpack and run out of energy reletively quick. I mean its an advanced tech, so it have advanced power source or something, or an increased range.
"Edit" Oh, I forgot. On the last day I lived, every single melee weapon I found seemed to break on the first hit. I wonder if its another time thing. My weapon seemed to jam when I fought HFS too. Made me unhappy. I still think the game doesnt like me. ><