cool puzzle idea! I would maybe introduce the pink tiles earlier- or remove one or two of the very early levels, as I was about to quit because I thought the game had shown me everything it could do-
the pink tiles added that extra level of tactical thinking that I enjoy!
I also wasn't sure at first if there was a way to 'erase' marks, because when I drew outside the lines there was no prompt or indication that I'd failed the level I could see, but maybe I just missed it!
I had fun, and it was a chill little puzzler, liked the groovy BGM that added to the vibes of it. Well done!