For those who are curious... the King's Games changes at level 50 (you fight the King). Doesn't seem to actually end or anything though. And Callisite is useless... you'll gain so much steel, the Callisite will never be worth it.
I must be doing something wrong... I just used archers and a few armored melee units and chose retreat every time. Walked through the whole game without an issue. Never even got to see a rank 5 card before beating beast.
Three stars... would have rated it higher because I like the concept, but the zoom was making the gameplay weak at times and it needed more creative opportunities for the player (ie. some way to prepare for a board).