Walkthrough: Grind to full upgrade the first launcher, distributing Critter points in Batties and Bat-Gang; Ignore the middle launchers - they are lots of investment for little gain when you can grind easily for the final launcher; once Batties and Bat-Gang are at 7, distributed remaining Critter points amongst your Passive upgrades.
The morale system is the point of this game. Aggressive moves will not be rewarded. Sit back, expose as few troops as possible, and play the war of attrition.
Bugs: Fighting the final boss if he offers a random encounter freezes the game; First Grave, 1st Degree Monster, Double Degree Monster, Genius monster in-game achievements are broken.