Lol hoped noone would ask, I'm still learning how to play, so made some embarassing mistakes like firing a Cannon into a tree (I thought it would blast the tree apart and kill everything behind it, because I know it tears through enemies, and I know enemies destroy obstacles as well, but then I looked behind the tree and still saw a massive horde of monsters behind it).
Maybe you should add that to the guide :P (it doesn't go through obstacles). Also I kept away from Bulldemons, and it finally occured to me that I wasn't sure if they ever charged diagonally, and so I "risked" engaging a couple on diagonals, and they didn't charge - which gave me a endgame strategy of trying to keep Bulldemons off my horizontal and vertical when they got close, but up to then I still got charged a lot.