The series also has one of the rare cases of introducing Suspiciously Similar Substitutes before the original characters left. About halfway into Season 2, Oliver's younger cousins, Simon and Crystal are introduced and get slowly integrated into the main cast throughout that season, eventually joining Oliver and Dee on some adventures. At the end of it, Oliver goes to college and passes the VisiCron on to them. The series lasts for another two more seasons with Simon and Crystal as the protagonists.
Every single subtype of the Mentor Archetype was probably used in this series at some point or another. Yes, even the evil ones!
Tropes featured in the series include:
- Agent Scully: Oliver.
- Bottle Episode: The first episode, "The Genius" takes place entirely in Oliver's room (save for a few shots of the exterior to it) with just three characters; himself, his mother, and the first historical figure sent to the present via the VisiCron, Albert Einstein.
- Cousin Oliver: Simon and Crystal, not Oliver!
- Denser and Wackier: Downplayed; the seasons featuring Simon and Crystal use more music where a lot of it is upbeat along with occasional sound effects compared to the generally sombre score used in the seasons featuring Oliver and Dee that isn't quite as played frequently and being devoid of sound effects. It also contains a few Formula-Breaking Episodes. That being said, it still retains the general themes and storylines.
- Evil Mentor: Vlad Tepes.
- Expy: Simon and Crystal where they manage to come on their own rather than being carbon copies of Oliver and Dee respectively.
- Getting Crap Past the Radar: Joan of Arc, in jail after the protagonists are arrested at a protest, remarks that her father dreamed of her riding with soldiers. Not knowing her future, he assumed she was a... She trails off without finishing, but at that moment, a scantily clad lady implied to be a street tramp walks past.
- Hollywood Atheist: Played straight with Dee's mother and possibly averted with Oliver, who's implied to be either an atheist or an agnostic.
- Loveable Rogue: Blackbeard.
- Magical Camera: A time travelling one also. Oliver's computer is able to see at any point and at any time of his choosing.
- Moose and Maple Syrup: The series is explicitly set in Canada, specifically Edmonton (the hometown of creator Josh Miller) where the city name is shown and mentioned a few times along with the Canadian flag being displayed several times while one of the main characters Simon plays hockey. A few episodes feature Canadian historical figures such as Frederick Banting, James Naismith, Mack Sennett, and Emily Carr.
- My Girl Is Not a Slut: One episode has Oliver unintentionally spreading rumors around school that he and Dee had sex (and remember that this is a kid's show). Of course, they just never call it by it's name. Naturally, Dee's popularity is threatened whereas Oliver's skyrockets.
- Relationship Upgrade: Oliver and Dee, at the end of the first season.
- San Dimas Time: Averted as when the historical figures return to their time period as soon as their 36 hours in the present are up, they return to the exact same time when they get transported to the present via the VisiCron.
- Second Episode Introduction: Dee is introduced in the second episode of the first season "Smart Aleck".
- Stealth Mentor: In the Season 2 finale, Oliver is one to himself.
- Treacherous Advisor: W.R. Hearst.