fallen mine: try and get to the last 2 upgrades and some reduced hire costs. put 2 mages on the bottom in front of where they go. then wait until they lvl then choose cold. You hsould have enough money to put the other 2 mages on the bottom. Don't upgrade them until the end. when you upgrading them; cold: cold,slow,generalism,destructor,massivedamage.
Fire:same thing.
At level 4 the hellfrogs should give you enough exp to lvl one of the mages, if not, wait for the bats to give the mages exp, then quickly lvl to massive damage. the goal here is to quickly upgrade the cold mages to hit more than 100, the bottom 2 are for support and to beat the embassy.
There are alot of very simple levels, and they would only require 1 or 2 people. For shaven road, if you have enough points to enhance the ranger, you can pretty much beat that level by being a poison warrior, berserk, generalism, ranger, damage, generalism, etc.
So RedGoldandGreen, even though you have found a strategy for a level, you have to put skill points into that class, if there is a specific class you use like the not so vast forest, you can upgrade warriors and you lives. If you put extra mages in places you don't need, you pretty much screw up you high advanced classes.
To beat the game, keep adding points to turret to 80. But as you increase lvls add some shield points. When it comes to lvl 15 shield is needed. To be the boss, find out where it goes and move a side and shoot it.