For those who think Unit Ignore is too hard, I found that it is a little expensive to do all explosion traps at first so I did spears, explosion, spears, explosion, etc. and it worked well so that, once I got to the point where I get tons of money, I could swap out spear traps for explosion traps which worked better.
For everyone stuck at the first castle, when you are at the unit selection screen you must click the soldiers TWICE so that you have 2 frontline units. Hope this helps
Stronger enemies should give more souls and I have a way for enemies having more than one soul make sense. Being as they are stronger they stole the souls from what they killed so they have more souls than weaker enemies. Other than that, great game 5/5 favourited