Great concept and very intuitive.
Zooming in and out seems to be somewhat bugged, and the game is extremely easy right now but I’m sure you know that. I made it a little more challenging for myself by restricting myself from placing adjacent to the cross I placed last turn. Still won, though.
Maybe picking up such limitations as you go further could be interesting? I was also thinking multiple enemies might be interesting, and perhaps variation between enemies/what they need to get to win.