Very fun game. The stages actually get a bit challenging as you progress and you have to strategize, but once you have a good army build going it gets very easy at least as far as the free version I've played let's you get.
To anyone having trouble, prioritize the rich peasants upgrade and the wizard's ice wall, then spam ranged units on every level. My only piece of criticism or feed back would precisely be that the melee units aren't viable with how the game and the score system work. It's far better to lay down ice walls for defense and spam dwarves and archers to handle the monster girls.
There seems to be room for a few additional units, so I would suggest adding some kind of healer to make the shield bearers and ugly bastards more viable, otherwise they just get trampled as the game gets harder and more and more monsters show up, no matter how many defense upgrades you buy (maybe a seamstress since health is just the state of your clothes? That would be funny.)
Besides that what little story there is is suitably funny for the ridiculous premise with a bit of intrigue regarding the player character. The art is good, the game over animations are good. Not much more to say.
I'll be following the development of this game, hope all goes well.