I didn't know about the tower defense genre before playing Kingdom Rush. I gave the game 5 stars, and then went to look for other TD games on Kongregate. So far, I have yet to find another worth over 3 stars. Other TD games are frankly dull. Kingdom Rush is anything but. You constantly have to be aware of various attackers, each with strengths and weaknesses, and adjust your defenses accordingly. You have four basic tower types, and a plethora of upgrades, which you have to prioritize. Excellent graphics and music complete the experience.
We will look into it!