it seems that upgrading an unit while in frenzy mode allow you to have twice the effect on fire rate so that you can get your units to attack really fast
lol i just can't believe it: i remember spending hours on last level some months ago and deciding to give up cause i was bored and now i beat this lvl ace+finish at... second try?? luck was with me it seems :)
it's perhaps a bit easy cause i see as a war i just put willpower to have whirl at 1s then full strenght the slowest weapon to have the biggest dmg every single item with +min/max or %dmg and after that i just change island and 2 shoot everything with circular atck and even boss need fast with that build which is pretty much stupid^^
 "Hands of War 3"){kind=icon}
 "Legend of Pandora"){kind=icon}
 "Hands of War Tower Defense"){kind=icon}
 "Amberial"){kind=icon}
 "Pirates Vs Ninjas"){kind=icon}
 "Magi: The Fallen World"){kind=icon}
Yep! There is a name for that psychological phenomenom, can't remember it right now tho =)