I love coding games, I had to read the tutorial to know what to do and it took some time, but the idea was cool. When I was switching between the modes it got maybe a glitch, because I could not return to Editing mode from Deleting mode. I had to refresh the page. But what was great is that you implemented automatic save of the level, so I returned where I have finished. The game need some finetuning but I enjoyed it!