Wonderful!
I though this game was the best zombie shooter game I've played on newgrounds... Very good job! the only thing is, you should add in a save feature... I was on Night 20 (i didn't know it was last) and I said "eh, i'll finish tomarrow" and closed the window... then I saw it was the last level and went back to beat it and... well.... thats why you need a save feature. Maybe the next one could have a more complex daytime system... Like if you set to build when you are at full, it starts to upgrade your wall to take less damage or something.