Hey, for a while there, I wanted to strangle you!
Sweet f'ing Lord this is a frustrating game, but I kept at it because it was wicked fun for the most part. I've been playing sporadically since this was under judgment, and I just finished about an hour ago. Man, it sure does take a hell of a lot of patience to get all the upgrades...
In my opinion, the attention span of the average Newgrounds patron is...less than ideal for this particular game. If you're planning on making any improvements, I think you first need to add the ability to select a level of difficulty or find some way to make it a bit easier for some people (allow the option to start with a bit of money, perhaps), because I'm not sure many will have the patience to get all the way through.
Also, those damned Mochi Ads! I don't want my own 'Zwinky' damn you! I think it'd be best for players if you'd tone those down a bit. I don't mind them for the most part, but this is pretty crazy.
Well, all in all, being the defense junkie I am, I had a f'ing blast kicking and screaming my way through this bitch, and oh yes, it is a bitch. Definitely not for those who want a twenty minute gaming session.
I really hope it makes it into the Defense Collection; I know I recommended it :)