Came here to leave a comment, but Sirius already said more or less what I wanted to say about the game, so I will just add a couple of things to it.
I actually loved the animations and functionality of the little flamethrower guy, it saved me from a zombie that come too close to me, so I did not have time to turn around, but simply attacking, the flamethrower guy fried it from behind, I thought it was really well-thought-out for this specific use case, didn't expect it to be a last minute add-in xD
As for what my critique would be, the towers that shoot lasers don't seem to react to damage immediately, so for a while I thought they were immune to it, turns out you just have to fry them well.
Really nice game, enjoyed it a lot!