This game is amazing and addicting! It could be better though, Like If you could add more weapons, Body Armor (for the zombies with guns) , More upgrades, an Endurance upgrade and more upgrades to make your weapons stronger! Again this is great game!
Random note: I had a Johnny Cash song stuck in my head today and I turned all the sound and music off to listen to it while I played and the song fit the game perfectly and made me feel like a badass! (The song was 'When the Man Comes Around")