When you can, try the game with 3 bomb birds in the back row, a minotaur in center, and 2 flying monkeys on the top left/right. NO fight will ever take more than 2 rounds, and even the end boss was a one round whippin.
I noticed that if you max out your mana regen upgrade (not during battle) that if you later upgrade your max mana amount (not during battle) that your mana just doesn't seem to replenish as fast....it's strange...
The game is a bit ridiculous. Even on easy mode, on a map where I possess ALL producing planets and all is left are enemy defensive planets I can't do squat. I've timed mass waves from 1, 2, 3, or even 4 planets to hit at the same time and it does almost nothing. Games are supposed to be fun, and while this is interesting, the frustration > fun. score: 1