This is the third time since A Wish Too Far that Trixie kisses Timmy, although it was only because Timmy's dark powers forced her. Despite this, Timmy had received a kiss from Trixie in "A Wish Too Far", "The Masked Magician" and, in the later episode, "Wishology", where they also tried to kiss again, but certain characters were in their way.
So far, this is the last appearance of Tad and Chad in the series.
Crocker breaks the fourth wall when he grabs the black circle at the end and shouts "I'M STILL NAKED!".
This is the ONLY episode where Wanda makes Cosmo hit himself after he said something nonsense. She must have copied that method from Timmy when he made Vicky hit herself with a pan using his dark powers.
During the scene where Cosmo, Wanda talk to Timmy, there is a mistake in animation. You can see Poof's eye color is pink similar to Wanda, instead of purple.
In real life, you cannot ask a scientist or others to do your science project for School Science Fair as that would be cheating (Tad and Chad might have gotten away with this by bribing the judges as they got away with things similar to this previously).