Some of the units look very pixelized, as if you just resized them. Coming from an artist you should smooth them out. Also after 1-4 the concept has gotten a bit old and I think you need to incorporate something new. Another good tip would be that you can see beyond where the units can go because when my units get up to the edge I'd like to see what they are up against.
I don't know why but everytime I play these games I get sticky keys. It's a great game nonetheless.
P.S. I feel like a noob, but how do I start over after I beat it?
If you need help with any, I have all of them. I had to google 5 of them.
http://imageshack.us/photo/my-images/812/ahahahahahah.png/
Copy paste that link^
Everybody always knows that zombies are the one and only type of creature that can create so much destruction. Screw all you skeletons and orcs, pshh..
I held an arrow untill after the level was done. I clicked the Next Level button which released the arrow, and then in the next level, the arrow killed me. Hmm, glitch anyone?
How to make money fast: Have 2 of the 4 (having 1 is fine too) robber, looter, City Cheif, reporter. Go back into an old level and all you do is fight bugs throughout it. If your strong enough you should win everytime. If you use Robber and Looter you get 2.5x as much money. Thats a lot of money. + rep for everyone to see