Eugene effortlessly passes the obstacle course, then goes back to carry Shorty over the finish line to prove a point. And when it looks like the hourglass has run out and Eugene has failed, it turns out he swiped the whistle, paying the Captain back for rigging the course by playing on Exact Words.
The episode applying safety rules about guns, albeit in the form of crossbows, which includes "Always keep the safety on the trigger".
Cass disarming Andrew of his sword with nothing but a dagger.
The entire climax for the episode has a truly epic fight between Cassandra and Andrew, on a hot-air balloon in flight. While this Moment of Awesome primarily belongs to Cassandra, the scene also gives Rapunzel, Eugene and even Pascal the opportunity to share in on the awesomeness.
In the flashback in the beginning, after losing his mother, little Pascal comes up to the tower and is attacked by the snake that ate his mother. Little Rapunzel shows up and knocks one of the snake's teeth out with her frying pan. The snake charges toward little Rapunzel, but the Badass Adorable little girl swats him right out of the tower with the frying pan, and the snake falls along way down.
After Pascal runs away, Rapunzel is out of her mind with worry. But when Cassandra tells Rapunzel that they have to briefly call off the search for him because she has a ton of royal responsibilities that day, she puts her foot down and goes full Mama Bear.
Cassandra: Listen, Rapunzel—
Rapunzel: No, you listen. Cancel everything. Lock down the castle, nothing gets done, until we find Pascal. Nothing is more important than that. Nothing! Is that clear?
Maximus's Big Damn Heroes moment. We've just seen that the combined forces of Rapunzel, Eugene and Cassandra can barely hold back one of the Gray Helmets. When Maximus shows up, he knocks out all seven Gray Helmets in twenty seconds flat.
Stalyan mocks Pascal (calling him a frog, etc.) but Pascal isn't intimidated by the fact that he's much smaller than her, and retaliates by shoving his long tongue in her face. She clearly didn't see that coming, and it confuses and shuts her up for a while.
The gang meets up with Hector, an extremist from the Brotherhood who gives even Adira a hard time. Cassandra tries to take him on, but seems hopelessly outmatched. At least until she reveals that she's been manuevering him closer to the cliff, and flings him off the edge in one swift motion.
In "The Brothers Hook", Rapunzel calls out Hookhand for demeaning Hookfoot's dream of dancing, especially when his own dream of playing piano was no different. Friend or not, Rapunzel knows where to draw the line.
In "Mirror Mirror", Eugene's smolder actaully works! And on Rapunzel's demon-mirror-double, no less.
What's more, when Rapunzel finally reprimands young Cassandra, she has to do so while whispering (so she doesn't wake up the attack dogs in the kennel). So she had to put the kid in her place without raising her voice. Now that's the mark of a good strict parent.
Even under the spell of a dream spell, Rapunzel is so determined to escape that her subconscious created a copy of herself that tried to wake herself up. Heck, Rapunzel's other self is a remarkable indication of how far she's come since season 1, having learned responsibility and the importance of making tough choices. She even lampshades that her "persistence" is what she likes most about herself.
Rapunzel telling off Matthews that he thought he could dangle an easy life in front of her, but from now on, she only follows her destiny.
Rapunzel realizes that she has the absolute reality-warping power over her dream and puts it to good use. She turns her chains into pretty little flowers, turns Matthews' fireball into a pink cupcake that promptly splashes all over the warlock, makes the tower disappear, takes control of the black rocks again, restores her hair, and breaks free.
The season finale gives us King Edmund, who curb-stomps Adira and later is easily able to take down all of Rapunzel's friends when they attack him all at once.
During the song "Everything I thought I knew", Eugene looks back on his memories from the series alone. He has many adventures to account for, showing that even as himself, Eugene Fitzerbert has accomplished more than he ever did as "Flynn Rider".
Regardless of how you feel about Cassandra's betrayal in the season finale, you gotta admit that her new outfit and look when she bonds with the Moonstone is pretty damn cool.