Such a unique and cool idea, combining between a puzzle and an auto battler. In level 4 there's more than 1 solution but the game doesn't register it. Besides that, pretty cool puzzle, good job!
Thanks for the kind words! Some of the levels indeed have multiple solutions, and all of them are valid! However, there is only one correct solution in level 4 (the star-shaped island with four red houses and one blue turret)