It was really good, but.....
After paying $1800 for the Nailgun and air compressor, then paying $150 ea for ammo, that it would be a better gun. The problem with it was that the tank would have that red bar recharge, and right when it did that, I would get hit be a goose. Another problem was that I was clicking really fast to kill the last animal and when the menu screen came up, I clicked to start the next round. And lastly, there was no pause button! I had $5000, 4 layers, and 2 turrets when my mom called, and right when I got back, I died.
On a final note, it was enjoyable, and I played several rounds, but I do think it needs more improvement.
BTW: Add more weapons and fort upgrades.