To the person who said, "Randomly clicking and combining things to try to figure out what's going on =/= puzzle": You're not familiar with the adventure game genre, are you?
Fantastic game. A lot of the new enemies really bump the difficulty up, perhaps too much, but the variety is welcome. I adore the Defense mode. Great stuff. 5/5
It seems a little overly simplistic. I do like the gameplay mechanics, though. The goalkeeper is pretty useless, and sometimes the wall of defenders is seemingly impenetrable.
I give it a 2/5, but that would definitely be higher, with more depth and a few tweaks.
Graphics are weak, but that could be forgivable. The concept is fun, but the gameplay kills it. You always take damage when fighting a zombie, so death is unavoidable. It's very lackluster. However, you do have something here. I'd refine it and keep working on it. It's definitely worth pursuing, but I don't think this particular build is going to work out.