hahaha good find Friky. Though after the game is out and people went as far as not only playing vs CPU but also having SC2 models, this game becomes very useless. Anyway, I'd solve it with this bug it has.
Thats an old one, i know a much better one.
If you have full upgrade on something, set the grahpics to lowest possible, the update buttons will scale down, if you click to the far right or left on the button (the last pixel), it will upgrade again.
When you do this with range it will not make any difference.
If you increase the attack speed, you will attack insanely fast, perfect for sniper.
If you take full in damage, you wont do any damage at all.
You will alsoget NaN (Not a Number), it gives you infinite money.
And this is another trick i found:
When you start, build a tower, right click and choose rewind then right click and choose forward, then start a new game. You will still have the building, but it wont be able to attack, so sell it and you will start with more money, you can repeat the process to sell alot of towers at once.
I found the first one by mistake while playing with lowest graphics, i simply spammed the upgrade button and it happened.
I found the second one with help from common sense