I see many suggested changes to towers and units by our dedicated players, but I just wanted to say that I wouldn't mind leaving everything as it is, and just a few more maps/modes.
Keep in mind what made Kingdom Rush so popular. Fast, simple, fun strategy.
No, I'm not saying there isn't room for improvement, what I'm saying is that I see many people suggesting more and more complex strategy.
That could ruin the original game concept.
Just ( yet ) another suggestion. No offence. Keep it simple.