Love the escalating difficulty, the last Extremly hard maps was tough :)
and the item/unit upgrade was brilliant for customizing for those bosses :) well made game.
Agreed with others it needs some more shortkeys for both Select a unit, but also for casting spells.
And the Hero with Regen seems a bit OP when my "tank" npc can do 1k ticks from regen hp spell and it only cost 30mana