@olinn are you capturing a lot of ports? As far as I can tell, ports don't generate soldiers. Morale (I think) decides the probability of how much damage your soldiers will do.
To those who say it's too hard - If you can't take the heat, get out of the kitchen.
Two things: 1) The scrolling
2) Level pack or sequel would be nice. :)
I think a storyline could do wonders, even if a small one. I know, "You're the bad guy, and the good guys want their gems back!", but how about just a little voice-over, before each map?
 "Zombies, Inc."){kind=icon}
 "Kingdom Rush"){kind=icon}
 "MegaCity"){kind=icon}
 "The Sandbox"){kind=icon}
 "A Quest for Idle"){kind=icon}
 "InvinciBall"){kind=icon}
 "Accelerator"){kind=icon}
 "Pinata Hunter"){kind=icon}
 "Hex Empire"){kind=icon}
 "GregManiacs"){kind=icon}
 "Penguin Overlords"){kind=icon}
 "Learn to Fly 2"){kind=icon}
 "ControlCraft"){kind=icon}
 "Cursed Treasure: Level Pack!"){kind=icon}
 "Don't Shit Your Pants"){kind=icon}