Great effort!
Superb flash game. There is some room for improvement, however it's not necessary.
I like the game engine, story, sound, graphics, character depth, unlockable items, .... pretty much everything is great.
The ending is BRILLIANT.
Meeting Jack was awesome.
Suggestions:
Further refine the inventory by splitting the consumable stuff into: into food, first-aid, stimulents.
Add a rubber chicken, light-saber, or some other cool weapon as a reward for completing the game.
Companion inventory can be implemented similar to the player inventory ( diablo2 style ).
Choice-driven story-line could be an interesting asset ( for example, add the "kill-your-own-infected-wife-and-ever yone-hates-you..-or-wait-for-her-to-e at-your-face" dilemma would have been interesting)
* There was a quiz-based zombie survival game I used to play on newgrounds which i always got to through the last-stand games. ( 2 actually... 1. - you go home to your wive; 2. you save your wife and family by getting medicine. )
That sort of "mini-game" could be an awesome opening for this one... Some text-based fun for zombie survival entuziasts.
I couldn't find any bugs to report other than the rare occurance of a zombie dying in mid-air and floating around.
Great job!
Keep it up.