all the heroes are dead weight later on anyways. they die way too easily. 1 attack from any boss from the extra stages will basically drop your fully upgraded hero to critically low hp if it doesn't outright kill them. they also spawn golems way too fast in addition to having more reach than your ranged units.
the game seems to be heavily imbalanced against the player. your hero is near useless in the new game since their death results in an instant loss. the final boss also can't hit something that is directly in front of him. not sure if this is intentional. the exp should be done based on something like damage dealt and damage taken rather than what seems to be a fixed amount of exp per stage. the range units also need to be able to "aim" rather than just attack a fixed distance. if they can't aim, they are near useless against short enemies that can take more than a few hits and don't flinch (the colored goblins).
 "Beez"){kind=icon}
 "Epic War 5"){kind=icon}
 "Medieval Rampage 2"){kind=icon}