Currently stacking higher symmetry past "Perfect symmetry" causes the level to hang- I can still quit the level and return to the map or use (waste) a Pause, but the next block never starts dropping. This is very easy to do by accident on level 4 as shown in the screenshot. https://steamcommunity.com/sharedfiles/filedetails/?id=2794925049 According to Player.log it's an ArgumentOutOfRangeException ("Index was out of range"), so my guess is that there is no behavior defined ...

Anyone have some hints for how to unlock the Elephant and Rainbow Achievements?