My initial idea was that the traps would be the main way to kill enemies, and if the player ran out of money or placed the traps poorly, they could still attack enemies directly — but only within a certain area of the map or after some time.
However, I think I underestimated the 4-day limit to finish and balance the game, so it ended up not making much sense to require so many hits to defeat each enemy.
Once again, thank you for your comment!