Yep! I don’t think it’s required to buy IAPs but they are appearing in the game about as fast as new waves of enemies. Heroes, gems, etc. it’s probably like previous kingdom rush games, but maybe a little more monetizy.
Super ironic too since the main plotline, such is there is, you play as the bad guy who is upset that his evil palace got turned into some sort of for-profit amusement park and is out for, well, vengeance. I don’t consider that a spoiler since it is literally the intro before you even play the first map.