That was a pretty clever idea! It's very easy to fall into just "play as the enemy" given the jams theme, but playing as the referee was very interesting!
The idea of calling out illegal moves AFTER they hit is great! Has some kind of risk-reward thing to it in which, even if you know the attack is coming, have to be careful to not call it out beforehand.
I guess the only thing I can suggest is adding more types of attacks to call out. Maybe having one which telegraph looks similar to a legal attack to make the player pay more attention to not call out legal attacks could be a good idea.
The animations were soooo smoth, loved them!
Overall a pretty fun experience. Thanks for sharing!