I love the idea of the game, reminds me a lot of rampart and graphics are so good.
I don't mean to be harsh but AI of the units is trash(most noticable with warriors), they all go and attack the same enemy and I usually feel cheated when warrior from left side goes all the way to right and leaves his side of the map undefended.
Maybe have Kingdom Rush style zone around baracks in which warriors will attack. No rally point just circle that they protect and attack once enemy enters. That shouldn't be too hard or time consuming to implement using circle collider and I think it would go a long way with QoL of the game.
Boss might be harder this way tho, so maybe having an option to circle protect or attack anywhere on the map would be good.
Sorry for rambling, I just found the loop of the game really interesting and was slightly triggered everytime all the warriors go to attack one enemy on left side while there is 3 on the right.