To win every level easily on hard upgrade market skill to max(level 5) ASAP and put points into ranged damage and melee damage (max if possible). Heal and Storm are also very useful along with a couple points in bless and healing potions. Just spam Paladin and Elf once you get them. Warrior and Ranger are fine until then. Use heal if needed and Storm if you want to speed the game up by killing faster. Don't bother with Taxman because they aren't worth taking up a unit slot and the market skill will give you all the money you need. Have Fun :D
On step seven if you have troubles with your background not being seemless change it too:
function onEnterFrame()
{
_x -= 1;
if( _x < -2110 )
{
_x += 4220;
}
}
 "Royal Offense"){kind=icon}
 "Waterfalls 3"){kind=icon}
 "Crush the Castle"){kind=icon}
 "Gravity Master"){kind=icon}
 "Shootorial #2"){kind=icon}
 "Towering Forever"){kind=icon}
 "filler"){kind=icon}