For Invincible enemies, it was a earth element and I was attacking with fire, but it wasn't even doing the thing were the enemy takes no damage as at least then it registers that it got it. Also the string was not burning for some reason, and I tried every attack with every dragon, it might be related to the enemies not taking damage.
Opening the game twice erased my save somehow, strange. Something to do with having two game windows open at once? Also I returned to title screen while massing z and now the game is soft locked, it makes menu sounds when pressing up or down, but nothing happens with any other button.
Because my save got erased, I'm going to replay the game and see if i can get past the rock now.
edit:
Sugar cubes spawned on you make no noise, but are still collected. Made me think I wasn't getting them for a bit though.
Ghosts spawning due it turning night instantly have hitboxes and so if you are where they spawn they instantly hit you upon it hitting night, however they will do the animation if you walk a bit away and then back.
There is no indication of changing time unless you open menu while in nest. Might want to hint at that somewhere.
The enemy strangeness continues, turns out for some reason in the previous save the enemies where not swapping between day and night forms correctly, instead they were all night in night form. Only now noticing, so the ghosts were always spawning, the fish were sleeping, and ice cubes all the time.
Now trumpet fish won't die despite all enemies being dead. I'm trapped in the room. Closing and re-opening the game did not fix this
The pause when attacking might have something to do with how close the enemy is, but that is just a guess.