Got a bug.
I put the cookie out of the cat's mouth and suddenly it disappeared. Turns out it lies between the first and the second floor in the middle screen.
Unreachable ;(
Weapons and towers are badly balanced, why should I ever use something different than rocket launchers/canons? And the hard achievement is just a grind for money, no increased difficulty after the capture of the last area. Too much repetitive gameplay because of these generator defenses. Other than that, nice optics and atmosphere, sound, zombies.
I'm amazed by the graphics. I never played something like that on a browser before. Nice work. And decent gameplay too. Could very well be a tutorial for a good full-priced game.