Thank you for your comment!
It's nice that I liked the style and mechanics.
Regarding the square that you need to stand on in order to kill the enemy: according to the plot, for ghosts it is a seal that holds them and its destruction leads to his expulsion. For robots - vulnerabilities in the robot's defense system. In terms of mechanics, I added this element for a more subtle strategy in the game. One and the same puzzle, but with a different arrangement of the seals of death, can be played in completely different ways.
I will try to work out the visual part to make it more comfortable to play.
Regarding the departure of the game. Can be more? Did the game window close or what exactly was happening?