"You try to enter 0000 into the keypad, but it requires a four digit number. FOUR DIGIT NUMBER. Do i need to make this more clear human?"
YES DEFINETELY
for survival:
one piercing tower to the far left and one on the far right facing each other. both equipped with a booster block on top.
place an eye block in the middle if the ghost boss appears and remove it when boss is killed.
it gets even easier because your sword damage increases with collected souls. i did about 50-60damage with each hit in the and
a wildcat with lion-force and beastman, two swords and maxed agility and strength is absolutly overpowered. 4 attacks with about 150 damage each that don't miss. and no enemy will hit you...
as a level up grants you a free heal try to beat the game as fast as possible. that way you will level up every few kills in the last two levels and they'll get very easy.
you can do the challenges later on.
level up power until level 15 (then you can kill even the "football-finger" with max 3 hits). then go for firerate to be able to saw down masses of enemies
you earn not enough iron. i got 9999 gold since level 3 but iron is just sufficent enough to heal my armies.
ps just play defensive for a while and you can max out everything in level 2. maybe even in level 1