Best. Zombie Survival Game. Ever.
Wow...
This game is amazing, I really just love it, it's so different to every other one, how you actually plan out the hours you spend doing stuff, rather than somehow collecting cash from dead zombies, and buying guns straight from thin air.
Lately my computer is being a bitch, so it means my browser or sometimes computer will just crash whilst playing this, which means I have to start over each time.
Maybe you could implement a save feature, for in between levels, but if you die, it saves over, so that you have to start again. (Hey, if a zombie rips you to pieces, you think you can just say "I'll restart this level!")
A very good game, I hope to see more of your work and possibly a sequel/remake to this?
Good luck with future projects.