good game just a few minor things you could do..
1) you could make a few resistant zombies like firefighters that are immune to poison or bandits immune to the arrows things like that
2) would be better if you could make a harder gameplay like easy medium hard harder and impossible
3)would be better if there was more to the game rather than putting them at the beginning of each map and just speeding it up and upgrading
if you do that this would be a 10/10 game atm its a 6/10 still pretty good but could be better
oh and 3RD COMMENT :D
if you click the red thing in cargo bay at begining of game you get a frozen red herring and aparently if you click a box there you get some black thongs :)
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