It's revealed that Sheen completely forgot about Libby and doesn't remember her since he went to space, a reference to how Libby was never mentioned even once in Planet Sheen.
It's also revealed that Sheen suffered brain damage when he crash landed onto Zeenu, explaining his stupider behavior in Planet Sheen and also forgetting his obsession with Ultra Lord.
Betty Quinlan makes a cameo appearance at the end of the crossover, where she decides to keep Mr. Nesmith as a pet.
Aseefa is paired up with Nick Dean when she went to Earth.
Spyro 2: Ripto's Rage! - The start of this crossover has Sally wanting to take a vacation away from the rain, similar to Spyro in in the second Spyro game in the original trilogy.
Legos - During a flashback Sally used Armos for her latest science project, a parody to the Legos.
Futurama - After flying back to Earth, Mr. Nesmith says in a deadpan tone, "I don't want to live on this planet anymore." A reference to the Futurama episode, A Clockwork Origin.
Scooby-Doo 2: Monsters Unleashed - When Dorkus nearly destorys Sheen and the others, Jimmy shows up to their rescue much to Dorkus' dismay asking him who does he think he is. Jimmy responds to his question, "Jimmy Neutron, Boy Genius!", a reference to the second live action Scooby movie, Scooby-Doo 2: Monsters Unleashed.