This game is a really awesome concept, but the tutorial doesn't explain it that well. Really more thought-provoking than you expect when you see the game.
Also please improve the visibility of enemies and allies with a red or blue glow or something, sometime they're hard to see. Text gets cut off by the UI too.
Needs a speed up button, some kind of XP system rather than days, better drops, selectable characters, and please have an end-battle screen where you can collect stuff you couldnt see. Things like drops and HP bars are hidden behind mouse and walls, HP is hard to see.
You should have bigger tooltips, and they should be always available e.g. showing the requirements to unlock new units and buildings. Also, put a return to campaign option in the menu. Also, most of the middle-tier units are useless. You have some work to do before the finished game.
Whenever I move an object, the 'footprint' stays there, so I can't put anything in that footprint or it seems use that footprint with another object.... So buggy :(