Glad you had a good time with it! Your favorite was actually also one of my favorites to write; if you type it in a couple times, that one has some pretty fun variants. Not sure if you saw it in a comment down below, but there is a list of all possible actions if you just want to try any more out.
It looks like what you did there was <null> the fish.
Seriously though, it looks like somehow a variable didn't get assigned anything. The online "leaderboard" type thing is pretty buggy right now. I should have known better than to think I could get that working with minimal testing, haha. Do you by any chance remember what you put in that led to that <null> response?