Vicky actually unintentionally saved Earth by easily defeating Mandie.
It's revealed that Mandie never loved Mark and only wanted to marry him so she can take over Yugopotamia. Although it's weird on how Mandie was just using Mark when on her first appearance, (New Squid In Town!) she seemed to love him. It's likely she was just acting or to have been a revenge mission since Mark left her at the alter and she must have hated him after that. (Although Timmy has always been able to wish her away even though Da Rules forbid interfering with true love altogether).
This is the last appearance of Princess Mandie in the series.
Mark's parents allow Mark to live on Earth.
First appearance of Mark's new identity: Justin Jake Ashton who will be his new human disguise from this point onward.
Apparently if fairies are shrunk down, their magic is diminished.
The ending title card played on the episode title, portraying Mark Chang as a king piece in chess.
ALF - Timmy being locked in a cage when he gets into puberty is a reference to the episode, Wild Thing, where ALF goes through a physiological and psychological transformation, and he must be locked in a cage.