Episode 1
Famous film director Quintin Smithee is coming to Retroville to make his next big movie, and Jimmy, Cindy, Libby, Sheen and Carl all have starring roles.
Episode 2
After a run in with a radiation belt in outer space, Jimmy, Cindy, Carl, Sheen and Libby are all endowed with super powers.
Episode 3
Jimmy, Sheen, and Carl travel 15 years into the future, only to find that some things have gone wrong. Can they right the past to save their future?
Episode 4
Jimmy's dad loses his job at the now-defunct automotive plant which means that the Neutrons may have to move to a new town. As a last-ditch effort to keep the family in Retroville, Hugh applies for a job as a toy inventor.
Episode 5
A trip gone wrong ends up turning even worse when Jimmy and Cindy get into an argument that winds up getting them stranded together.
Episode 6
Jimmy is recruited by the most prestigious science college in the country to be their new superstar student. But when he gets there, Jimmy becomes the unwitting target of rival student, Seymour Nimmelfarb.
Episode 7
On a trip to Planet Schmengy, a strange alien substance attaches itself to Carl's face.
Episode 8
The Neutron family has gathered to celebrate Great Aunt Amanda's birthday. When Jimmy's present explodes, everyone suspects him of fowl.
Episode 9
Jimmy's new mission from the BTSO is to follow Beautiful Gorgeous. He takes the job and he discovers that she and Jet Fusion are getting married!
Episode 10
In Retroville, Sheen is just an average hyperactive kid. But in Shangri Llama, he is known as The Chosen One, or One Who Puts Foot Behind Head.
Episode 11
When the entire population of Retroville is accidentally hit by Jimmy's shrink ray, the Space Bandits abduct everyone with the nefarious plan of marketing and selling them throughout the galaxy as living dolls.
Episode 12
A new TV show turns everyone in Retroville into mindless and exceedingly cheerful zombies.
Episode 13
To impress Betty Quinlan, Jimmy performs a magic show using a cheap magic kit that's full of his own technological upgrades.
Episode 14
The evil Jimmy clone is back, and he's reconfigured the cloning device to make an evil clone of the Earth with an alarming side effect – the real Earth is starting to disappear.
Episode 15
The boys travel to the Bahama Quadrangle to disprove the myth of the disappearances associated with the mysterious site.
Episode 16
Carl's pen pal, Elke Elkberg from Sweden, is coming to Retroville to meet him, and Carl is in a panic.
Episode 17
Jimmy is framed for a break in at the Retroville Bank. When Carl and Sheen attempt to free him from his incarceration, the three boys end up on a chain gang together.
Episode 18
Jimmy places a funny chip into Hugh's new Flippy puppet when he insists on using it for Career Day at school. But Jimmy soon learns that Flippy is stealing his dad's mind and has to save him before Flippy disposes of him.
Episode 19
When Jimmy hides a time displacement device in the teachers' transportation to the annual education convention, the entire faculty of Lindberg Elementary is sent into temporary time limbo.
Episode 20
The kids become news anchors for a local television network.
Episode 21
Eustace Strych is back, and he's still determined to humiliatingly defeat Jimmy. Now the race to find an energy source on Mars is on! Who will win?
Episode 22
Sheen's dad, Mr. Estevez desperately wants to impress his son, so he pretends he is a superhero.
Episode 23
Goddard is disqualified from the Retroville Pet Show because he is not technically a real dog.
