Nice game, good job.
Zombie shooters are always nice.
Only thing I think might of been different are levels (waves) there could be more and you
could of balanced them between saving the survivors on one level then the next level
just killing a certain amount of zombies, after that collecting enough radio parts and so on.
This would give you more levels and more time to collect money so you could buy more
weapons, because I just got to the shotgun and hawk and one or two mines, but from another
point, player has to choose carefully his weapons.
Survival was ok, but it could of been the same as campaign just with more waves.
Last but not least, I know my English is not good, so what can I say,
but you should check your English in game.
In overall, good and decent game, I enjoyed playing it.