In case you didn't know, you can change all your equip at the same time during a fight. At first I thought you could only change one piece at a time but you can change 3. It's really useful for the last boss.
For the last level I used 4 rows with archers and 4 rows of ice traps. Then I spammed every hot keys and had to rebuild 2 archers who died.
Protip: you cant win if you are not using the hot-keys.
The best stat for the archer that you recruit is speed. If you put every stats in there and boost it with some items, you will get "Infinity" Damage Per Second.
Good game but I've beaten it three times now. (yeah I do need a life).
Quick advice : your double jump is gonna bug if you do it while touching a wall and moving towards it at the same time.