great tower defense ,, thankx alot .. I just had fun playing throw all the levels ..

Excellent tower defense

The cow thing totally worked for me. I like how a leak doesn't necessarily mean that you're going to permanently lose 'HP'
I think it's fairly interesting that the basic towers can become so powerful. I haven't seen a lot of that in tower defense games. So far, the towers all seem pretty well balanced. I haven't tried the poison or psi-attack ones yet, but I'm sure they will be as effective as all the other towers.
The only suggestions I would like to make would be an inclusion of walls, since that's what I end up using most of my non-upgraded basic towers for, and perhaps more techs to research.
Hats off to you.

Good Stuff

The game itself has a few flaws, but overall it's quite addicting and enjoyable. The upgrades are interesting and some unique. I found the cow mechanic to work quite well, and be rather humorous. The graphics were decent, and sounds were good. The interface could have used a bit of work, but that's nothing too major. The large black enemy seemed a bit too strong for how early it appeared, but perhaps I was doing something wrong. Overall, it was a solid TD that could just used a bit more polish. Regardless, it was still fun, and it was obvious that a lot of work went into it.